Move linting job to CircleCI

.circleci/config.yml

@@ -72,6 +72,30 @@ jobs:
               docker push "${DOCKERHUB_REPO}:${CIRCLE_TAG}"
             fi
 
+  lint:
+    docker:
+      - image: circleci/python:3.7.9
+    steps:
+      - checkout
+      - run:
+          name: Install dependencies
+          command: |
+            pip install --upgrade cardboardlint pylint
+      - run:
+          name: Run linter
+          command: |
+            set -ex
+            # Check if branch can be merged with master (if failing script will stop due to set -e)
+            git config user.email "you@example.com"
+            git config user.name "Your Name"
+            git merge --no-commit --no-ff origin/master
+
+            # Undo merge changes if any
+            git reset --hard $CIRCLE_BRANCH
+
+            # Lint differences against master
+            cardboardlinter --refspec origin/master -n auto;
+
 workflows:
   version: 2
   build-deploy:
@@ -87,3 +111,7 @@ workflows:
           filters:
             tags:
               only: /.*/
+
+  lint:
+    jobs:
+      - lint