LoadError: cannot load such file -- http/headers

After installing `berkshelf-api` from the gem I'm receiving `LoadError: cannot load such file -- http/headers`. Here's the full log:

    $ rvm use 2.0.0
    Using /Users/benlemasurier/.rvm/gems/ruby-2.0.0-p451


    $ rvm gemset create berks-api && rvm gemset use berks-api
    ruby-2.0.0-p451 - #gemset created /Users/benlemasurier/.rvm/gems/ruby-2.0.0-p451@berks-api
    ruby-2.0.0-p451 - #generating berks-api wrappers.........
    Using ruby-2.0.0-p451 with gemset berks-api


    $ gem install berkshelf-api
    Fetching: semverse-1.1.0.gem (100%)
    Successfully installed semverse-1.1.0
    Fetching: retryable-1.3.5.gem (100%)
    Successfully installed retryable-1.3.5
    Fetching: net-http-persistent-2.9.4.gem (100%)
    Successfully installed net-http-persistent-2.9.4
    Fetching: mixlib-log-1.6.0.gem (100%)
    Successfully installed mixlib-log-1.6.0
    Fetching: mixlib-authentication-1.3.0.gem (100%)
    Successfully installed mixlib-authentication-1.3.0
    Fetching: hashie-2.1.1.gem (100%)
    Successfully installed hashie-2.1.1
    Fetching: multipart-post-2.0.0.gem (100%)
    Successfully installed multipart-post-2.0.0
    Fetching: faraday-0.9.0.gem (100%)
    Successfully installed faraday-0.9.0
    Fetching: erubis-2.7.0.gem (100%)
    Successfully installed erubis-2.7.0
    Fetching: nio4r-1.0.0.gem (100%)
    Building native extensions.  This could take a while...
    Successfully installed nio4r-1.0.0
    Fetching: hitimes-1.2.1.gem (100%)
    Building native extensions.  This could take a while...
    Successfully installed hitimes-1.2.1
    Fetching: timers-2.0.0.gem (100%)
    Successfully installed timers-2.0.0
    Fetching: celluloid-0.16.0.pre.gem (100%)
    Successfully installed celluloid-0.16.0.pre
    Fetching: celluloid-io-0.16.0.pre.gem (100%)
    Successfully installed celluloid-io-0.16.0.pre
    Fetching: buff-ruby_engine-0.1.0.gem (100%)
    Successfully installed buff-ruby_engine-0.1.0
    Fetching: buff-shell_out-0.1.1.gem (100%)
    Successfully installed buff-shell_out-0.1.1
    Fetching: buff-ignore-1.1.1.gem (100%)
    Successfully installed buff-ignore-1.1.1
    Fetching: buff-extensions-0.5.0.gem (100%)
    Successfully installed buff-extensions-0.5.0
    Fetching: varia_model-0.3.2.gem (100%)
    Successfully installed varia_model-0.3.2
    Fetching: buff-config-0.4.0.gem (100%)
    Successfully installed buff-config-0.4.0
    Fetching: addressable-2.3.6.gem (100%)
    Successfully installed addressable-2.3.6
    Fetching: ridley-3.0.0.gem (100%)
    Successfully installed ridley-3.0.0
    Fetching: websocket_parser-0.1.6.gem (100%)
    Successfully installed websocket_parser-0.1.6
    Fetching: http_parser.rb-0.6.0.gem (100%)
    Building native extensions.  This could take a while...
    Successfully installed http_parser.rb-0.6.0
    Fetching: http-0.5.0.gem (100%)
    Successfully installed http-0.5.0
    Fetching: reel-0.5.0.pre.gem (100%)
    Successfully installed reel-0.5.0.pre
    Fetching: builder-3.2.2.gem (100%)
    Successfully installed builder-3.2.2
    Fetching: thread_safe-0.3.3.gem (100%)
    Successfully installed thread_safe-0.3.3
    Fetching: ice_nine-0.11.0.gem (100%)
    Successfully installed ice_nine-0.11.0
    Fetching: descendants_tracker-0.0.4.gem (100%)
    Successfully installed descendants_tracker-0.0.4
    Fetching: axiom-types-0.1.1.gem (100%)
    Successfully installed axiom-types-0.1.1
    Fetching: coercible-1.0.0.gem (100%)
    Successfully installed coercible-1.0.0
    Fetching: equalizer-0.0.9.gem (100%)
    Successfully installed equalizer-0.0.9
    Fetching: virtus-1.0.2.gem (100%)
    Successfully installed virtus-1.0.2
    Fetching: multi_xml-0.5.5.gem (100%)
    Successfully installed multi_xml-0.5.5
    Fetching: multi_json-1.9.2.gem (100%)
    Successfully installed multi_json-1.9.2
    Fetching: minitest-5.3.3.gem (100%)
    Successfully installed minitest-5.3.3
    Fetching: tzinfo-1.1.0.gem (100%)
    Successfully installed tzinfo-1.1.0
    Fetching: i18n-0.6.9.gem (100%)
    Successfully installed i18n-0.6.9
    Fetching: activesupport-4.1.0.gem (100%)
    Successfully installed activesupport-4.1.0
    Fetching: rack-1.5.2.gem (100%)
    Successfully installed rack-1.5.2
    Fetching: rack-accept-0.4.5.gem (100%)
    Successfully installed rack-accept-0.4.5
    Fetching: rack-mount-0.8.3.gem (100%)
    Successfully installed rack-mount-0.8.3
    Fetching: grape-0.7.0.gem (100%)
    Successfully installed grape-0.7.0
    Fetching: msgpack-0.5.8.gem (100%)
    Building native extensions.  This could take a while...
    Successfully installed msgpack-0.5.8
    Fetching: grape-msgpack-0.1.1.gem (100%)
    Successfully installed grape-msgpack-0.1.1
    Fetching: ffi-1.9.3.gem (100%)
    Building native extensions.  This could take a while...
    Successfully installed ffi-1.9.3
    Fetching: archive-0.0.6.gem (100%)
    Successfully installed archive-0.0.6
    Fetching: sawyer-0.5.4.gem (100%)
    Successfully installed sawyer-0.5.4
    Fetching: octokit-2.7.2.gem (100%)
    Successfully installed octokit-2.7.2
    Fetching: berkshelf-api-1.2.1.gem (100%)
    Successfully installed berkshelf-api-1.2.1
    51 gems installed


    $ berks-api -v -d
    I, [2014-04-17T13:39:54.080713 #43007]  INFO -- : Cache manager starting...
    I, [2014-04-17T13:39:54.100454 #43007]  INFO -- : Cache Builder starting...
    E, [2014-04-17T13:39:54.212524 #43007] ERROR -- : Actor crashed!
    LoadError: cannot load such file -- http/headers
    	/Users/benlemasurier/.rvm/rubies/ruby-2.0.0-p451/lib/ruby/site_ruby/2.0.0/rubygems/core_ext/kernel_require.rb:55:in `require'
    	/Users/benlemasurier/.rvm/rubies/ruby-2.0.0-p451/lib/ruby/site_ruby/2.0.0/rubygems/core_ext/kernel_require.rb:55:in `require'
    	/Users/benlemasurier/.rvm/gems/ruby-2.0.0-p451@berks-api/gems/reel-0.5.0.pre/lib/reel/response.rb:1:in `<top (required)>'
    	/Users/benlemasurier/.rvm/rubies/ruby-2.0.0-p451/lib/ruby/site_ruby/2.0.0/rubygems/core_ext/kernel_require.rb:55:in `require'
    	/Users/benlemasurier/.rvm/rubies/ruby-2.0.0-p451/lib/ruby/site_ruby/2.0.0/rubygems/core_ext/kernel_require.rb:55:in `require'
    	/Users/benlemasurier/.rvm/gems/ruby-2.0.0-p451@berks-api/gems/reel-0.5.0.pre/lib/reel.rb:12:in `<top (required)>'
    	/Users/benlemasurier/.rvm/rubies/ruby-2.0.0-p451/lib/ruby/site_ruby/2.0.0/rubygems/core_ext/kernel_require.rb:55:in `require'
    	/Users/benlemasurier/.rvm/rubies/ruby-2.0.0-p451/lib/ruby/site_ruby/2.0.0/rubygems/core_ext/kernel_require.rb:55:in `require'
    	/Users/benlemasurier/.rvm/gems/ruby-2.0.0-p451@berks-api/gems/berkshelf-api-1.2.1/lib/berkshelf/api/rest_gateway.rb:1:in `<top (required)>'
    	/Users/benlemasurier/.rvm/gems/ruby-2.0.0-p451@berks-api/gems/berkshelf-api-1.2.1/lib/berkshelf/api/application.rb:19:in `require_relative'
    	/Users/benlemasurier/.rvm/gems/ruby-2.0.0-p451@berks-api/gems/berkshelf-api-1.2.1/lib/berkshelf/api/application.rb:19:in `initialize'
    	/Users/benlemasurier/.rvm/gems/ruby-2.0.0-p451@berks-api/gems/celluloid-0.16.0.pre/lib/celluloid/calls.rb:26:in `public_send'
    	/Users/benlemasurier/.rvm/gems/ruby-2.0.0-p451@berks-api/gems/celluloid-0.16.0.pre/lib/celluloid/calls.rb:26:in `dispatch'
    	/Users/benlemasurier/.rvm/gems/ruby-2.0.0-p451@berks-api/gems/celluloid-0.16.0.pre/lib/celluloid/calls.rb:63:in `dispatch'
    	/Users/benlemasurier/.rvm/gems/ruby-2.0.0-p451@berks-api/gems/celluloid-0.16.0.pre/lib/celluloid/cell.rb:60:in `block in invoke'
    	/Users/benlemasurier/.rvm/gems/ruby-2.0.0-p451@berks-api/gems/celluloid-0.16.0.pre/lib/celluloid/cell.rb:71:in `block in task'
    	/Users/benlemasurier/.rvm/gems/ruby-2.0.0-p451@berks-api/gems/celluloid-0.16.0.pre/lib/celluloid/actor.rb:362:in `block in task'
    	/Users/benlemasurier/.rvm/gems/ruby-2.0.0-p451@berks-api/gems/celluloid-0.16.0.pre/lib/celluloid/tasks.rb:55:in `block in initialize'
    	/Users/benlemasurier/.rvm/gems/ruby-2.0.0-p451@berks-api/gems/celluloid-0.16.0.pre/lib/celluloid/tasks/task_fiber.rb:15:in `block in create'
    D, [2014-04-17T13:39:54.212836 #43007] DEBUG -- : Terminating 34 actors...
    I, [2014-04-17T13:39:54.213713 #43007]  INFO -- : Cache Builder shutting down...
    I, [2014-04-17T13:39:54.213947 #43007]  INFO -- : Cache Manager shutting down...
    W, [2014-04-17T13:39:54.233285 #43007]  WARN -- : Terminating task: type=:finalizer, meta={:method_name=>:__shutdown__}, status=:callwait
    	Celluloid::TaskFiber backtrace unavailable. Please try `Celluloid.task_class = Celluloid::TaskThread` if you need backtraces here.
    W, [2014-04-17T13:39:54.234946 #43007]  WARN -- : Terminating task: type=:finalizer, meta={:method_name=>:__shutdown__}, status=:callwait
    	Celluloid::TaskFiber backtrace unavailable. Please try `Celluloid.task_class = Celluloid::TaskThread` if you need backtraces here.
    W, [2014-04-17T13:39:54.235294 #43007]  WARN -- : Terminating task: type=:finalizer, meta={:method_name=>:__shutdown__}, status=:callwait
    	Celluloid::TaskFiber backtrace unavailable. Please try `Celluloid.task_class = Celluloid::TaskThread` if you need backtraces here.
    /Users/benlemasurier/.rvm/rubies/ruby-2.0.0-p451/lib/ruby/site_ruby/2.0.0/rubygems/core_ext/kernel_require.rb:55:in `require': cannot load such file -- http/headers (LoadError)
    	from /Users/benlemasurier/.rvm/rubies/ruby-2.0.0-p451/lib/ruby/site_ruby/2.0.0/rubygems/core_ext/kernel_require.rb:55:in `require'
    	from /Users/benlemasurier/.rvm/gems/ruby-2.0.0-p451@berks-api/gems/reel-0.5.0.pre/lib/reel/response.rb:1:in `<top (required)>'
    	from /Users/benlemasurier/.rvm/rubies/ruby-2.0.0-p451/lib/ruby/site_ruby/2.0.0/rubygems/core_ext/kernel_require.rb:55:in `require'
    	from /Users/benlemasurier/.rvm/rubies/ruby-2.0.0-p451/lib/ruby/site_ruby/2.0.0/rubygems/core_ext/kernel_require.rb:55:in `require'
    	from /Users/benlemasurier/.rvm/gems/ruby-2.0.0-p451@berks-api/gems/reel-0.5.0.pre/lib/reel.rb:12:in `<top (required)>'
    	from /Users/benlemasurier/.rvm/rubies/ruby-2.0.0-p451/lib/ruby/site_ruby/2.0.0/rubygems/core_ext/kernel_require.rb:55:in `require'
    	from /Users/benlemasurier/.rvm/rubies/ruby-2.0.0-p451/lib/ruby/site_ruby/2.0.0/rubygems/core_ext/kernel_require.rb:55:in `require'
    	from /Users/benlemasurier/.rvm/gems/ruby-2.0.0-p451@berks-api/gems/berkshelf-api-1.2.1/lib/berkshelf/api/rest_gateway.rb:1:in `<top (required)>'
    	from /Users/benlemasurier/.rvm/gems/ruby-2.0.0-p451@berks-api/gems/berkshelf-api-1.2.1/lib/berkshelf/api/application.rb:19:in `require_relative'
    	from /Users/benlemasurier/.rvm/gems/ruby-2.0.0-p451@berks-api/gems/berkshelf-api-1.2.1/lib/berkshelf/api/application.rb:19:in `initialize'
    	from /Users/benlemasurier/.rvm/gems/ruby-2.0.0-p451@berks-api/gems/celluloid-0.16.0.pre/lib/celluloid/calls.rb:26:in `public_send'
    	from /Users/benlemasurier/.rvm/gems/ruby-2.0.0-p451@berks-api/gems/celluloid-0.16.0.pre/lib/celluloid/calls.rb:26:in `dispatch'
    	from /Users/benlemasurier/.rvm/gems/ruby-2.0.0-p451@berks-api/gems/celluloid-0.16.0.pre/lib/celluloid/calls.rb:63:in `dispatch'
    	from /Users/benlemasurier/.rvm/gems/ruby-2.0.0-p451@berks-api/gems/celluloid-0.16.0.pre/lib/celluloid/cell.rb:60:in `block in invoke'
    	from /Users/benlemasurier/.rvm/gems/ruby-2.0.0-p451@berks-api/gems/celluloid-0.16.0.pre/lib/celluloid/cell.rb:71:in `block in task'
    	from /Users/benlemasurier/.rvm/gems/ruby-2.0.0-p451@berks-api/gems/celluloid-0.16.0.pre/lib/celluloid/actor.rb:362:in `block in task'
    	from /Users/benlemasurier/.rvm/gems/ruby-2.0.0-p451@berks-api/gems/celluloid-0.16.0.pre/lib/celluloid/tasks.rb:55:in `block in initialize'
    	from /Users/benlemasurier/.rvm/gems/ruby-2.0.0-p451@berks-api/gems/celluloid-0.16.0.pre/lib/celluloid/tasks/task_fiber.rb:15:in `block in create'
    	from (celluloid):0:in `remote procedure call'
    	from /Users/benlemasurier/.rvm/gems/ruby-2.0.0-p451@berks-api/gems/celluloid-0.16.0.pre/lib/celluloid/calls.rb:92:in `value'
    	from /Users/benlemasurier/.rvm/gems/ruby-2.0.0-p451@berks-api/gems/celluloid-0.16.0.pre/lib/celluloid/proxies/sync_proxy.rb:33:in `method_missing'
    	from /Users/benlemasurier/.rvm/gems/ruby-2.0.0-p451@berks-api/gems/celluloid-0.16.0.pre/lib/celluloid/proxies/cell_proxy.rb:17:in `_send_'
    	from /Users/benlemasurier/.rvm/gems/ruby-2.0.0-p451@berks-api/gems/celluloid-0.16.0.pre/lib/celluloid.rb:169:in `new'
    	from /Users/benlemasurier/.rvm/gems/ruby-2.0.0-p451@berks-api/gems/berkshelf-api-1.2.1/lib/berkshelf/api/application.rb:143:in `run!'
    	from /Users/benlemasurier/.rvm/gems/ruby-2.0.0-p451@berks-api/gems/berkshelf-api-1.2.1/lib/berkshelf/api/application.rb:119:in `block in run'
    	from /Users/benlemasurier/.rvm/gems/ruby-2.0.0-p451@berks-api/gems/berkshelf-api-1.2.1/lib/berkshelf/api/application.rb:118:in `loop'
    	from /Users/benlemasurier/.rvm/gems/ruby-2.0.0-p451@berks-api/gems/berkshelf-api-1.2.1/lib/berkshelf/api/application.rb:118:in `run'
    	from /Users/benlemasurier/.rvm/gems/ruby-2.0.0-p451@berks-api/gems/berkshelf-api-1.2.1/lib/berkshelf/api/srv_ctl.rb:63:in `start'
    	from /Users/benlemasurier/.rvm/gems/ruby-2.0.0-p451@berks-api/gems/berkshelf-api-1.2.1/lib/berkshelf/api/srv_ctl.rb:48:in `run'
    	from /Users/benlemasurier/.rvm/gems/ruby-2.0.0-p451@berks-api/gems/berkshelf-api-1.2.1/bin/berks-api:5:in `<top (required)>'
    	from /Users/benlemasurier/.rvm/gems/ruby-2.0.0-p451@berks-api/bin/berks-api:23:in `load'
    	from /Users/benlemasurier/.rvm/gems/ruby-2.0.0-p451@berks-api/bin/berks-api:23:in `<main>'
    	from /Users/benlemasurier/.rvm/gems/ruby-2.0.0-p451@berks-api/bin/ruby_executable_hooks:15:in `eval'
    	from /Users/benlemasurier/.rvm/gems/ruby-2.0.0-p451@berks-api/bin/ruby_executable_hooks:15:in `<main>'