[LNT] Declare support for Python 3.6+

Summary:
With all tests passing on Python 3.6, this commit declare support for
Python 3.6+. We can lower the requirement later if necessary.

Reviewers: cmatthews, hubert.reinterpretcast, leandron, PrzemekWirkus, kristof.beyls

Reviewed By: PrzemekWirkus

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D71085

Author: Thomas Preud'homme

setup.py

@@ -9,8 +9,8 @@
 import sys
 from setuptools import setup, find_packages, Extension
 
-if sys.version_info < (2, 7):
-    raise RuntimeError("Python 2.7 or higher required.")
+if sys.version_info < (3, 6) and sys.version_info[:2] != (2, 7):
+    raise RuntimeError("Python 2.7 or Python 3.6 or higher required.")
 
 cflags = []
 
@@ -128,5 +128,5 @@
 
     ext_modules=[cPerf],
 
-    python_requires='>=2.7',
+    python_requires='>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, !=3.4.*, !=3.5.*',
 )