set shebang in gem bins to system ruby
Merge pull request #471 from indirect/master

ensure bootstrap uses system ruby
Short term hack to unbreak boxen-git-credential on 10.8 systems
Merge pull request #475 from seanknox/master

Unbreak boxen-git-credential on 10.8 systems
Clarify where to create the new git repo.

Be more explicit about where the new repo should be located. It's much
easier to set up a repo on the internet. This was implied before and now
it's explicit.

The first time I helped a colleague set this up, we used a local repo.
Since we didn't know what we were doing, we screwed it up pretty badly.
This bit of text might allow others not to make the same mistake we did.
Merge pull request #477 from mattr-/explain-repo-location

Clarify where to create the new git repo.
Merge remote-tracking branch 'upsteam/master'