fix #1642 - add py 3.8 and 3.9 to classifiers

Author: alexcjohnson

setup.py

@@ -61,6 +61,8 @@ def read_req_file(req_type):
         "Programming Language :: Python :: 3.5",
         "Programming Language :: Python :: 3.6",
         "Programming Language :: Python :: 3.7",
+        "Programming Language :: Python :: 3.8",
+        "Programming Language :: Python :: 3.9",
         "Topic :: Database :: Front-Ends",
         "Topic :: Office/Business :: Financial :: Spreadsheet",
         "Topic :: Scientific/Engineering :: Visualization",