Added Python 3.8 to classifiers in setup.py.

Author: jonathanslenders

setup.py

@@ -49,6 +49,7 @@ def get_version(package):
         "Programming Language :: Python :: 3",
         "Programming Language :: Python :: 3.6",
         "Programming Language :: Python :: 3.7",
+        "Programming Language :: Python :: 3.8",
         "Programming Language :: Python :: 3 :: Only",
         "Programming Language :: Python",
         "Topic :: Software Development",