Advantages of checking in the Gemfile.lock when developing gems:

• A known good state to fall back on and do incremental updates
• Being able to instantly work on an old project
• No random failures for every new contributor
• No “Bundler could not find compatible versions for gem” errors when Gemfile changes and users have an old lock

To test against newest versions, add `before_install: rm Gemfile.lock` to .travis.yml … same coverage, less drama.