No check for byebug

[prpetten]

byebug is the new debugging standard for ruby 2.x, and adding 'byebug' to a file works just like dropping in a 'debugger' in ruby 1.x.

byebug github repo: https://github.com/deivid-rodriguez/byebug

Would like to check for 'byebug' as well as 'debugger'

[Fryie]

i second this :)

[mpapis]

closing in favour of #207

[jish]

https://github.com/jish/pre-commit/pull/224