Add helm linting step to gitlab-ci

.gitlab-ci.yml

@@ -9,12 +9,24 @@ variables:
   DOCKER_DRIVER: overlay2
 
 stages:
-  - test
+  - lint_python
+  - lint_helm
   - deploy
 
+lint_helm_on_merge_request:
+    image: alpine/helm
+    stage: lint_python
+    script:
+     - echo "Linting Helm chart"
+     - helm lint ./helm
+    rules:
+      - changes:
+        - helm/*
+
+
 lint_python_on_merge_request:
     image: python:alpine
-    stage: test
+    stage: lint_python
     script:
      - echo "Linting Python code"
      - pip install --upgrade -q pip && pip install -q black && black --fast --check .