Compat with Ruby 2.0.0/Bundler 1.3

Bundler 1.3 generates gems differently - it follows the "dashes mean
directories" convention, which it didn't before.  As such, I'm now
parsing bundler's output to figure out what file to include
in the scaffolded binfile.

Further, I had to upgrade minitest and mocha to get things working
with Ruby 2.0.0