Migrate mypy config from setup.cfg to mypy.ini.

Author: scottwernervt

mypy.ini

@@ -0,0 +1,5 @@
+[mypy]
+ignore_missing_imports = true
+warn_unreachable = true
+warn_unused_ignores = true
+warn_redundant_casts = true

setup.cfg

@@ -1,23 +1,2 @@
 [bdist_wheel]
 python-tag = py3
-
-[flake8]
-max-line-length = 80
-max-complexity = 18
-select = C,E,F,W,B,B950
-ignore = E203,E501,W503
-exclude =
-    .git
-    .eggs
-    .tox
-    __pycache__
-    docs/conf.py
-    old
-    build
-    dist
-
-[mypy]
-ignore_missing_imports = true
-warn_unreachable = true
-warn_unused_ignores = true
-warn_redundant_casts = true