[Buildbot] #2828: move github_buildbot out of contrib

[Buildbot trac]

#2828: move github_buildbot out of contrib
------------------------+--------------------
Reporter:  dustin       |       Owner:
    Type:  enhancement  |      Status:  new
Priority:  major        |   Milestone:  0.9.+
 Version:  0.8.9        |  Resolution:
Keywords:  git, github  |
------------------------+--------------------

Comment (by sa2ajj):

 See also #2889.

--
Ticket URL: <http://trac.buildbot.net/ticket/2828#comment:2>
Buildbot <http://buildbot.net/>
Buildbot: build/test automation