Remove bundle binstub and regenerate other binstubs

# What's up

I've been seeing these annoying warnings when running `bin/rspec spec`:

![screen shot 2014-05-14 at 16 22 26](https://cloud.githubusercontent.com/assets/62895/2973188/952bf5b2-db7b-11e3-8728-28b83b7b5495.png)

This PR removes the `bundle` binstub (inception?) and regenerates the other binstubs so that:

![screen shot 2014-05-14 at 16 23 29](https://cloud.githubusercontent.com/assets/62895/2973205/b9a92838-db7b-11e3-8e47-48be18041a60.png)