PYTHON-2009 Add Python 3.8 to trove classifiers

Author: behackett

setup.py

@@ -384,6 +384,7 @@ def build_extension(self, ext):
         "Programming Language :: Python :: 3.5",
         "Programming Language :: Python :: 3.6",
         "Programming Language :: Python :: 3.7",
+        "Programming Language :: Python :: 3.8",
         "Programming Language :: Python :: Implementation :: CPython",
         "Programming Language :: Python :: Implementation :: PyPy",
         "Topic :: Database"],