Merge branch 'update-gitlab-git' into 'master'

Updated gitlab_git to 9.0.1

This includes gitlab-org/gitlab_git!69 and will hopefully solve
gitlab-org/gitlab-ce#13808.

See merge request !3123

Gemfile.lock

@@ -358,7 +358,7 @@ GEM
       posix-spawn (~> 0.3)
     gitlab_emoji (0.3.1)
       gemojione (~> 2.2, >= 2.2.1)
-    gitlab_git (9.0.0)
+    gitlab_git (9.0.1)
       activesupport (~> 4.0)
       charlock_holmes (~> 0.7.3)
       github-linguist (~> 4.7.0)