want to try github actions without python 3.6

Author: dleskosky

setup.py

@@ -39,7 +39,7 @@ def read(fname):
             "Intended Audience :: Developers",
             "Intended Audience :: Science/Research",
             "License :: OSI Approved :: MIT License",
-            "Programming Language :: Python :: 3.6",
+            # "Programming Language :: Python :: 3.6",
             "Programming Language :: Python :: 3.7",
             "Programming Language :: Python :: 3.8",
             "Topic :: Scientific/Engineering",