shipit_bot_uplift: Only run merge test on mercurial patches, refs #202.
shipit_bot_uplift: Only run merge test on mercurial patches, refs #202.

fixes #210

andrei987/services,garbas/mozilla-releng-services,srfraser/services,mozilla-releng/services,srfraser/services,srfraser/services,garbas/mozilla-releng-services,srfraser/services,La0/mozilla-relengapi,lundjordan/services,andrei987/services,La0/mozilla-relengapi,La0/mozilla-relengapi,La0/mozilla-relengapi,lundjordan/services,lundjordan/services,mozilla-releng/services,garbas/mozilla-releng-services,garbas/mozilla-releng-services,mozilla-releng/services,andrei987/services,mozilla-releng/services,andrei987/services,lundjordan/services