PEP-8: Add github action for pep8

.github/workflows/pep8.yml

@@ -0,0 +1,22 @@
+name: pep8
+
+on:
+  push
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - name: Set up Python
+      uses: actions/setup-python@v2
+      with:
+        python-version: '3.x'
+    - name: Install dependencies
+      run: |
+        python -m pip install --upgrade pip
+        pip install pycodestyle
+    - name: Run pycodestyle
+      run: |
+        pycodestyle --show-source --show-pep8 app/*
+        pycodestyle --show-source --show-pep8 test/*