SDK-1853: Add Python3.9 and 3.9-dev to versions

Author: emmas-yoti

.github/workflows/tests.yaml

@@ -13,7 +13,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: [2.7, 3.4, 3.5, "3.5-dev", 3.6, "3.6-dev", 3.7, "3.7-dev", 3.8, "3.8-dev"]
+        python-version: [2.7, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, "3.9-dev"]
 
     steps:
       - uses: actions/checkout@v2