Enable python 3.6 support

Author: ppizarror

.readthedocs.yml

@@ -15,7 +15,7 @@ sphinx:
 
 # Optionally set the version of Python and requirements required to build your docs
 python:
-  version: 3.7
+  version: 3.8
   install:
     - method: pip
       path: .

README.rst

@@ -14,9 +14,9 @@ pygame-menu
     :target: https://opensource.org/licenses/MIT
     :alt: License MIT
 
-.. image:: https://img.shields.io/badge/python-3.7+-red.svg
+.. image:: https://img.shields.io/badge/python-3.6+-red.svg
     :target: https://www.python.org/downloads
-    :alt: Python 3.7+
+    :alt: Python 3.6+
 
 .. image:: https://img.shields.io/badge/pygame-1.9.3%2B%2F2.0%2B-orange
     :target: https://www.pygame.org

pygame_menu/version.py

@@ -34,6 +34,6 @@ def __str__(self) -> str:
     patch = property(lambda self: self[2])
 
 
-vernum = Version(4, 3, 7)
+vernum = Version(4, 3, 8)
 ver = str(vernum)
 rev = ''