Remove 3.6 from setup.py

Author: CMoncur

setup.py

@@ -30,7 +30,6 @@
           "Programming Language :: Python :: Implementation :: CPython",
           "Programming Language :: Python :: Implementation :: PyPy",
           "Programming Language :: Python :: 3",
-          "Programming Language :: Python :: 3.6",
           "Programming Language :: Python :: 3.7",
           "Programming Language :: Python :: 3.8",
           "Programming Language :: Python :: 3.9",