blackify codebase (#286)

.github/workflows/zblack.yml

@@ -0,0 +1,12 @@
+name: Black Python Linter
+
+on: [push,pull_request]
+
+jobs:
+  black:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2.3.2
+      - uses: lgeiger/black-action@v1.0.1
+        with:
+          args: " --check . "

test_requirements.txt

@@ -1,4 +1,5 @@
 # requirements for testing
+black==20.8b1
 docker==4.1.0
 pytest==5.2.2
 PySocks==1.7.1