Bug 1430011 - Use the git package in the toolchain-build docker image. r=gps

--HG--
extra : rebase_source : ac7ccc85496a8447550c721734d6584c0899921f

taskcluster/ci/docker-image/kind.yml

@@ -27,6 +27,7 @@ jobs:
     symbol: I(toolchain)
     packages:
       - deb7-cmake
+      - deb7-git
       - deb7-mercurial
       - deb7-ninja
       - deb7-python