Add back in working branch for jobs to use

Change-Id: I7de671b5ab2a8ae3ff73680cdf584c8c5b579cbb
diff --git a/turbo_hipster/lib/gerrit-git-prep.sh b/turbo_hipster/lib/gerrit-git-prep.sh
index 1b9e546..5636241 100755
--- a/turbo_hipster/lib/gerrit-git-prep.sh
+++ b/turbo_hipster/lib/gerrit-git-prep.sh
@@ -97,3 +97,7 @@
     git submodule sync
     git submodule update --init
 fi
+
+# Added for turbo-hipster
+git branch -D working || true
+git checkout -b working