Simplify python_requires

setup.py

diff --git a/setup.py b/setup.py
index 9c589aa..a9b5d90 100644
--- a/setup.py
+++ b/setup.py
@@ -287,5 +287,5 @@
 
         distclass=Distribution,
         cmdclass=cmdclass,
-        python_requires='!=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, !=3.4.*, !=3.5.*',
+        python_requires='>=3.6',
     )