Create black.yml

Author: phobson

.github/workflows/black.yml

@@ -0,0 +1,13 @@
+name: black
+
+on: [pull_request]
+
+jobs:
+  black:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - name: Black Code Formatter
+      uses: lgeiger/black-action@v1.0.1
+      with:
+        args: ". --check"