Fix infinite loop and GLI-2 upgrade

Version 0.7.0 no longer works for me on OSX.  I have two issues:

1) GLI updates

This seems to have been discussed here.

https://github.com/schacon/showoff/pull/198
https://github.com/schacon/showoff/pull/193

2) Infinite loop

For me this loop never exists:

https://github.com/schacon/showoff/blob/ae11f6a3c82e96319ed6e37ea9ae092e9d871230/lib/showoff.rb#L509

I am not a ruby developer but this fix appeared to work:

http://stackoverflow.com/questions/12072865/calling-a-sinatra-app-instance-method-from-testcase