Update README.rst

Author: dfunckt

README.rst

@@ -84,7 +84,7 @@ Table of Contents
 Requirements
 ============
 
-``rules`` requires Python 3.6 or newer. The last version to support Python 2.7
+``rules`` requires Python 3.7 or newer. The last version to support Python 2.7
 is ``rules`` 2.2. It can optionally integrate with Django, in which case
 requires Django 2.2 or newer.