issue usabilla#135

* attempts to add python linting via github actions
* adds flake8 linting triggered on pull request and push

.github/workflows/linting.yml

@@ -1,12 +1,22 @@
-name: Linting
+name: Python Linting
 
-on: [push, pull_request]
+on: [push]
 
 jobs:
-  styles:
-    runs-on: ubuntu-18.04
-    name: Linting
+  build:
+
+    runs-on: ubuntu-latest
+
     steps:
-      - uses: actions/checkout@master
-      - uses: actions/setup-python@v1
-      - uses: WhyNotHugo/[email protected]
+    - uses: actions/checkout@v1
+    - name: Set up Python 3.7
+      uses: actions/setup-python@v1
+      with:
+        python-version: 3.7
+    - name: Lint with flake8
+      run: |
+        pip install flake8
+        # stop the build if there are Python syntax errors or undefined names
+        flake8 . --count --select=E9,F63,F7,F82 --show-source --statistics
+        # exit-zero treats all errors as warnings. The GitHub editor is 127 chars wide
+        flake8 . --count --exit-zero --max-complexity=10 --max-line-length=127 --statistics