[Buildbot] #2828: move github_buildbot out of contrib

[Buildbot trac]

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

 I especially like the addition of support for --secret, which allows
 Buildbot to at least trust that the request is from GitHub.

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Ticket URL: <http://trac.buildbot.net/ticket/2828#comment:1>
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