Remove Gitolite from buse

Originally created by @intrigeri on #14587 (Redmine)

Beware! We could maybe satisfy our Git needs on buse with a much simpler setup, without Gitolite.

Gitolite v2 is not in Jessie.

The main difficulties I expect are: hooks handling (we do complicated stuff there) and Redmine integration (we do crazy stuff there, that’s not been managed with Puppet so far).

Resources:

• http://gitolite.com/gitolite/migr/
• https://github.com/sitaramc/gitolite-doc/blob/master/archive/migr.mkd
• https://github.com/sitaramc/gitolite-doc/blob/master/archive/g2migr-example.mkd

Feature Branch: puppet-tails:bugfix/14587-gitolite-on-buse

Related issues

• Copied from #10093 (closed)