Add appraisal as dev dependency
Fix tests with appraisal
Update travis config to use appraisal
Removing appraisal gemfile locks
There is no reason to keep them. Just as we don't keep Gemfile.lock for a gem,
there is no point in enforcing particular version of gems when testing
different versions of rails with appraisal.
Better naming convention for appraisals
Whitespace fixes
Include appraisal's gemfile locks as recommended
Merge pull request #4 from jakubmal/appraisal

Integration with appraisal.

Closes #1