Fix commit compliance checking

It was broken since we modified check_commits.sh few weeks ago

Changelog: None

Signed-off-by: Lluis Campos <lluis.campos@northern.tech>

.gitlab-ci.yml

@@ -10,9 +10,19 @@ stages:
 
 test:
   stage: test
-  script:
+  before_script:
     - apk add --no-cache bash perl-utils
-    - git clone git://github.com/mendersoftware/mendertesting
+    # Rename the branch we're on, so that it's not in the way for the
+    # subsequent fetch. It's ok if this fails, it just means we're not on any
+    # branch.
+    - git branch -m temp-branch || true
+    # Git trick: Fetch directly into our local branches instead of remote
+    # branches.
+    - git fetch origin 'refs/heads/*:refs/heads/*'
+    # Get last remaining tags, if any.
+    - git fetch --tags origin
+    - git clone http://github.com/mendersoftware/mendertesting
+  script:
     # Check commit compliance.
     - mendertesting/check_commits.sh
     # Check licenses