Created a Github Action for Python's Black formatter. (#112)

* Setup Python Linter

* Setup Rust linting

* Fix Rust lint

* Fixing rust lint again.

* Disabling rust linting, due to bug in current rustfmt release.

* Delete rustlint, cause @nikita-b has a working version.

.github/workflows/black.yml

@@ -0,0 +1,11 @@
+name: Python Lint
+
+on: [push, pull_request]
+
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-python@v2
+      - uses: psf/black@stable