Update README

Author: robgolding

README.rst

@@ -10,7 +10,7 @@ tasklib
 tasklib is a Python library for interacting with taskwarrior_ databases, using
 a queryset API similar to that of Django's ORM.
 
-Supports Python 2.7, and 3.4 - 3.8 with taskwarrior 2.1.x and above.
+Supports Python 3.5 and above, with taskwarrior 2.1.x and above.
 Older versions of taskwarrior are untested and may not work.
 
 Requirements