Add JRuby back to travis now that dep-selector supports it

This reverts commit fbf603f88ac712f665ec7909dc9d59f25df3b1ff.
Update README badges
Merge pull request #38 from berkshelf/sethvargo/update_badges

Update README badges
Merge pull request #36 from danielsdeleo/restore-jruby

Add JRuby back to travis now that dep-selector supports it
Remove Ruby benchmark
Merge pull request #32 from berkshelf/sethvargo/better_resolver

Resolver speed optimizations