update deps; remove unused mypy extension

docs/releases/release-checklist.md

@@ -14,6 +14,7 @@
  - [ ] all debug prints removed  
  - [ ] setup.py version is updated 
  - [ ] __init__.py version is updated
+ - [ ] types check (for the most part) `./venv/Scripts/python.exe -m mypy /path/to/python_bindings/types.py`
  - [ ] pip install of release branch works.   
      - [ ] All Gooey Examples run and work as expected
  - [ ] pypi is updated 

gooey/gui/components/widgets/bases.py

@@ -3,7 +3,6 @@ from functools import reduce
 from typing import Optional, Callable, Any, Type, Union
 
 import wx  # type: ignore
-from mypy_extensions import KwArg
 
 from gooey.gui import formatters, events
 from gooey.gui.util import wx_util
@@ -16,10 +15,7 @@ from gooey.python_bindings import types as t
 
 
 class BaseWidget(wx.Panel):
-    widget_class: Union[
-        Type[Any],
-        Callable[[Any, KwArg(Any)], Any]
-    ]
+    widget_class: Any
 
     def arrange(self, label, text):
         raise NotImplementedError

setup.py

@@ -13,9 +13,10 @@ deps = [
     'psutil>=5.4.2',
     'colored>=1.3.93',
     'pygtrie>=2.3.3',
-    're-wx>=0.0.1',
+    're-wx>=0.0.9',
     'typing-extensions==3.10.0.2',
-    'wxpython>=4.1.0'
+    'wxpython>=4.1.0',
+    'dataclasses>=0.8',
 ]
 
 setup(
@@ -27,6 +28,7 @@ setup(
     description=('Turn (almost) any command line program into a full GUI '
                  'application with one line'),
     license='MIT',
+    python_requires='>=3.6',
     packages=find_packages(),
     install_requires=deps,
     include_package_data=True,