Add mypy configuration section to setup.cfg

setup.cfg

@@ -46,3 +46,18 @@ include =
 [options.entry_points]
 console_scripts =
 	rsrcfork = rsrcfork.__main__:main
+
+[mypy]
+files=rsrcfork/**/*.py
+python_version = 3.6
+
+disallow_untyped_calls = True
+disallow_untyped_defs = True
+disallow_untyped_decorators = True
+
+no_implicit_optional = True
+
+warn_unused_ignores = True
+warn_unreachable = True
+
+warn_redundant_casts = True