Fix 'copy' support

Up until this point, we've been keeping all engineers up-to-date by
symlink'ing everything into a canonical 'git_hooks' repo that is updated
via Chef runs.

For public release, I want 'copy' to be the default install option,
making this project more self-contained. While it would save a few bytes
to symlink into the gem's source directory, it feels much cleaner to me
to just copy the relevant bits.

Change-Id: Ibc59ba5a02fec6d56c059d3555b0ecc38b54f32b
Reviewed-on: https://gerrit.causes.com/22340
Tested-by: Aiden Scandella <aiden@causes.com>
Reviewed-by: Shane da Silva <shane@causes.com>
Remove errant `require 'rubygems'`

Not needed or appreciated, especially since this file is not loading any
other libraries.

Change-Id: Ia09fd400797dc46027e38269729e797bdabceb06
Reviewed-on: https://gerrit.causes.com/22347
Tested-by: Aiden Scandella <aiden@causes.com>
Reviewed-by: Shane da Silva <shane@causes.com>
Reviewed-by: Joe Lencioni <joe.lencioni@causes.com>