Fixup gemspec

There's important stuff in bin and config that should be packaged with
the gem.

Additionally, remove dependency on `git`, since I have no untracked
files in these directories.

Change-Id: I163725c7ce4057fd874e6d57c23be53ab1eab425
Reviewed-on: https://gerrit.causes.com/22750
Tested-by: Aiden Scandella <aiden@causes.com>
Reviewed-by: Joe Lencioni <joe.lencioni@causes.com>
Remove path munging from hook runner

This was in place for development, so that I'd be using the library path
from the development version, not the installed gem.

Change-Id: Ibf08997505cda268f0c57c8f35cd0b8993c309ee
Reviewed-on: https://gerrit.causes.com/22753
Tested-by: Aiden Scandella <aiden@causes.com>
Reviewed-by: Joe Lencioni <joe.lencioni@causes.com>