reformatted code using black, isort + CI

Author: salehahr

.github/workflows/lint.yml

@@ -0,0 +1,29 @@
+name: lint
+
+on:
+  push:
+    branches:
+      - master
+      - refactor
+  pull_request:
+    branches:
+      - master
+      - refactor
+
+jobs:
+  sort-imports:
+    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 isort and black
+        run: |
+          python -m pip install --upgrade pip
+          pip install isort black
+      - name: Run isort and black
+        run: |
+          isort .
+          black .