update supported python versions

.github/workflows/pull_request-test-python.yaml

@@ -13,6 +13,8 @@ jobs:
         - 2.7
         - 3.5.7
         - 3.6.9
+        - 3.7.5
+        - 3.8.0
     steps:
     - name: Set up Python
       uses: actions/setup-python@v1

python/az/aro/setup.py

@@ -20,9 +20,10 @@ CLASSIFIERS = [
     'Programming Language :: Python :: 2',
     'Programming Language :: Python :: 2.7',
     'Programming Language :: Python :: 3',
-    'Programming Language :: Python :: 3.4',
     'Programming Language :: Python :: 3.5',
     'Programming Language :: Python :: 3.6',
+    'Programming Language :: Python :: 3.7',
+    'Programming Language :: Python :: 3.8',
     'License :: OSI Approved :: Apache Software License',
 ]