[travis-ci] testing against different bundler versions
[travis-ci] testing against different bundler versions
fedenusy/warbler,fedenusy/warbler,idibon/warbler,idibon/warbler,ctreatma/warbler,idibon/warbler,fedenusy/warbler,ctreatma/warbler,ctreatma/warbler,idibon/warbler,ctreatma/warbler,fedenusy/warbler