Adds Pylint linting to a proper CI pipeline running on GitHub's Actions

.github/workflows/linting.yml

@@ -0,0 +1,25 @@
+---
+name: Linting
+
+on: [push, pull_request]
+
+jobs:
+  build:
+    name: Run Pylint on CDNUpdates sources
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v2
+
+      - uses: actions/setup-python@v2
+
+      - run: |
+          python -m pip install --upgrade pip
+          pip install pylint
+
+      - run: |
+          pylint \
+            --module-rgx='CDN.*' \
+            --disable=relative-beyond-top-level \
+            --ignored-modules=sublime,sublime_plugin \
+            *.py

CDNContent.py

@@ -18,7 +18,7 @@ from .CDNConstants import (
 from .CDNUtils import log_message
 
 
-class CDNContent:
+class CDNContent:  # pylint: disable=too-few-public-methods
     """
     This class run verifies whether found CDN are up to date.
     Checks (try to) rely on the CDN provider's API, or on GitHub directly.