Add missing comma

Author: B-Stefan

setup.py

@@ -34,9 +34,9 @@
         'Topic :: Software Development :: Libraries :: Python Modules',
         'License :: OSI Approved :: Apache Software License',
         'Programming Language :: Python :: 3.4',
-        'Programming Language :: Python :: 3.5'
-        'Programming Language :: Python :: 3.6'
-        'Programming Language :: Python :: 3.7'
+        'Programming Language :: Python :: 3.5',
+        'Programming Language :: Python :: 3.6',
+        'Programming Language :: Python :: 3.7',
         'Programming Language :: Python :: 3.8'
     ],
     license="Apache License 2.0",