Adding python 3.9 to CI

Author: adamcharnock

.circleci/config.yml

@@ -6,10 +6,12 @@ workflows:
     jobs:
       - test-37
       - test-38
+      - test-39
       - combine_coverage_reports:
           requires:
             - test-37
             - test-38
+            - test-39
 
   build_and_deploy_docs:
     jobs:
@@ -60,7 +62,14 @@ jobs:
   test-38:
     <<: *test-template
     docker:
-      - image: circleci/python:3.8.1
+      - image: circleci/python:3.8.5
+      - image: postgres:9.6.2
+      - image: redis:5
+
+  test-39:
+    <<: *test-template
+    docker:
+      - image: circleci/python:3.9.1
       - image: postgres:9.6.2
       - image: redis:5