feat: requires-python (#536)

* feat: requires-python

refactor: updating to current proposal

fix: add tests and fix a few issues

docs: Update mostly from @joerick

docs: update README from readthedocs

* refactor: pull out config file reading

* fix: always assume highest Python patch version

* refactor: try new design

* refactor: function and bump MyPy to 0.800

* fix: tighten AST to call only, add docs

* fix: address review points from @joerick

setup.cfg

@@ -32,6 +32,7 @@ install_requires =
     toml
     certifi
     bracex
+    packaging
     typing_extensions; python_version < '3.8'
 
 [options.package_data]
@@ -42,17 +43,17 @@ dev =
     click
     mkdocs-include-markdown-plugin==2.1.1
     mkdocs==1.0.4
-    mypy
     pip-tools
     pygithub
+    ghapi
     pymdown-extensions
-    pytest
+    pytest>=4
     pytest-timeout
     pyyaml
     requests
     typing-extensions
-    packaging>=20.8
     rich>=9.6
+    mypy>=0.800
 
 [options.packages.find]
 include =
@@ -83,14 +84,14 @@ junit_family=xunit2
 
 [mypy]
 python_version = 3.6
-files = cibuildwheel,test,unit_test,bin
+files = cibuildwheel/*.py,test/**/*.py,unit_test/**/*.py
 warn_unused_configs = True
 warn_redundant_casts = True
 
-[mypy-test.*]
+[mypy-test.*,mypy-unit_test.*]
 check_untyped_defs = True
 
-[mypy-cibuildwheel.*,unit_test.*]
+[mypy-cibuildwheel.*]
 disallow_any_generics = True
 disallow_subclassing_any = True
 disallow_untyped_calls = True
@@ -122,6 +123,9 @@ ignore_missing_imports = True
 [mypy-bracex.*]
 ignore_missing_imports = True
 
+[mypy-importlib_resources.*]
+ignore_missing_imports = True
+
 [tool:isort]
 profile=black
 multi_line_output=3