bash_it custom exports issue

[SebastianZaha]

bash_it custom exports contain RUBYOPT="-Ku". This is making ruby 2.0 issue a warning, which in turn messes up rubymine when you add the 2.0 sdk.

[roderik]

We needed the -Ku because we had UTF-8 encoding issues in some tools we used. You could move the RUBYOPT content to an attribute so you can override it in your config file. I'll be happy to merge a pull request.