add more python versions for testing, precommit config

Author: adamgayoso

.github/workflows/test.yml

@@ -15,7 +15,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: [3.6, 3.7]
+        python-version: [3.6, 3.7, 3.8, 3.9]
 
     steps:
     - uses: actions/checkout@v2

.pre-commit-config.yaml

@@ -1,10 +1,15 @@
 repos:
--   repo: https://gitlab.com/pycqa/flake8
-    rev: 3.7.7
-    hooks:
-    -   id: flake8
--   repo: https://github.com/ambv/black
-    rev: stable
-    hooks:
-    - id: black
-      language_version: python3.7
+    - repo: https://github.com/psf/black
+      rev: 22.1.0
+      hooks:
+          - id: black
+    - repo: https://github.com/PyCQA/flake8
+      rev: 4.0.1
+      hooks:
+          - id: flake8
+    - repo: https://github.com/pycqa/isort
+      rev: 5.10.1
+      hooks:
+          - id: isort
+            name: isort (python)
+            additional_dependencies: [toml]