fix cyclic dependency bug
add test
Use semver for Travis Ruby 2.1
Update to buff-config ~> 0.4
Merge pull request #1178 from optimizely/fix_infinite_lock

Fix infinite lock check
formatting
Merge pull request #1180 from berkshelf/sethvargo/bump_buff_config

Update to buff-config ~> 0.4
Create a subclass of the shell instead of a module