Add default bundler binstubs, move generate script

[bdewater]

The community has settled on a bin/ folder for scripts, I've added default generated scripts from bundle gem to facilitate with experimenting and moved the generate script there.

Remove rubygems require form generate per https://gist.github.com/rtomayko/54177 - tested and it still works fine.

[bpollack]

@dtykocki How do you feel about this? I know you were generally not in favor of adding to scripts/ in the past, but is adding to bin in this context okay?

[bpollack]

@bdewater If this is something you want, I'm happy to rebase and land this today; just let me know.

[bpollack]

@bdewater I rebased this and made tests pass. Happy to merge if you'd like.