Adopt black in pre-commit

Update using black for formatting python code, automatically apply
change in the pre-commit hook.

More info about black:
https://black.readthedocs.io/en/stable/

Signed-off-by: Wayne Sun <gsun@redhat.com>

.pre-commit-config.yaml

@@ -1,22 +1,18 @@
 # configuration for pre-commit git hooks
-files: ^(src/pylero)
+exclude: '^docs'
 repos:
 - repo: https://github.com/asottile/reorder_python_imports
-  rev: v2.6.0
+  rev: v3.8.2
   hooks:
   - id: reorder-python-imports
-    language_version: python3
 - repo: https://github.com/pre-commit/pre-commit-hooks
-  rev: v4.0.1
+  rev: v4.3.0
   hooks:
   - id: trailing-whitespace
-    language_version: python3
   - id: end-of-file-fixer
-    language_version: python3
   - id: debug-statements
-    language_version: python3
-- repo: https://github.com/pycqa/flake8
-  rev: 3.9.2
+  - id: detect-private-key
+- repo: https://github.com/psf/black
+  rev: 22.6.0
   hooks:
-  - id: flake8
-    language_version: python3
+  - id: black

README.md

@@ -292,13 +292,13 @@ $ pip install pre-commit
 $ pre-commit autoupdate && pre-commit run -a
 ```
 
-Pre-commit will ensure that the changes you made are not in violation of PEP8 standards.
+Pre-commit will ensure that the changes you made are not in violation of PEP8 standards and automatically apply black fixes.
 
-We recommend `autopep8` to fix any pre-commit failures by running below or you are free to use any formatters which can resolve pre-commit failures with least possible diff.
+We recommend `black` to automatically fix any pre-commit failures.
 
 ``` python
-$ pip install autopep8
-$ autopep8 --in-place <edited_file.py>
+$ pip install black
+$ black <edited_file.py>
 ```
 
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