Merge remote-tracking branch 'upstream/master'

Conflicts:
	.gitignore
	.travis.yml
	CHANGELOG.md
	Gemfile
	Gemfile.lock
	LICENSE
	README.md
	Rakefile
	bin/compile
	config/cdn.yml
	hatchet.json
	lib/language_pack.rb
	lib/language_pack/base.rb
	lib/language_pack/cache.rb
	lib/language_pack/disable_deploys.rb
	lib/language_pack/fetcher.rb
	lib/language_pack/helpers/bundler_wrapper.rb
	lib/language_pack/helpers/plugin_installer.rb
	lib/language_pack/helpers/rake_runner.rb
	lib/language_pack/helpers/stale_file_cleaner.rb
	lib/language_pack/instrument.rb
	lib/language_pack/metadata.rb
	lib/language_pack/no_lockfile.rb
	lib/language_pack/rack.rb
	lib/language_pack/rails2.rb
	lib/language_pack/rails3.rb
	lib/language_pack/rails4.rb
	lib/language_pack/ruby.rb
	lib/language_pack/ruby_version.rb
	lib/language_pack/shell_helpers.rb
	lib/language_pack/version.rb
	spec/bugs_spec.rb
	spec/default_cache_spec.rb
	spec/gem_detect_errors_spec.rb
	spec/helpers/bundler_wrapper_spec.rb
	spec/helpers/fetcher_spec.rb
	spec/helpers/rake_runner_spec.rb
	spec/helpers/ruby_version_spec.rb
	spec/helpers/stale_file_cleaner_spec.rb
	spec/no_lockfile_spec.rb
	spec/rails23_spec.rb
	spec/rails3_spec.rb
	spec/rails4_spec.rb
	spec/rubies_spec.rb
	spec/ruby_spec.rb
	spec/spec_helper.rb
	spec/user_env_compile_edge_case_spec.rb
	vendor/dotenv.rb
	vendor/lpxc.rb
	vendor/syck_hack.rb