fix: fix flake8 config (#231)

* fix: update flake8 config in order not to conflict with black

* fix: update python version for black

Author: jonathlela

Makefile

@@ -6,7 +6,7 @@ source_code_check_format:
 
 .PHONY: source_code_format
 source_code_format:
-	black --line-length 120 --target-version py37 . && \
+	black --line-length 120 --target-version py39 . && \
 	isort .
 	$(MAKE) source_code_check_format
 

setup.cfg

@@ -30,4 +30,7 @@ py_version=39
 known_local_folder=kernl
 
 [flake8]
-max-line-length = 120
+max-line-length = 120
+extend-ignore =
+    # See https://github.com/PyCQA/pycodestyle/issues/373
+    E203,