Run tests with officially released version of Python 3.9

Photonios · Photonios · commit d696d9c49a71 · 2020-10-07T11:00:05.000+03:00
diff --git a/.circleci/config.yml b/.circleci/config.yml
@@ -81,7 +81,7 @@ jobs:
 
     test-python39:
         docker:
-            - image: python:3.9-rc-alpine3.10
+            - image: python:3.9-alpine
             - image: postgres:11.0
               environment:
                   POSTGRES_DB: 'psqlextra'
