Run tests on Python 3.9

Author: Anthchirp

.azure-pipelines.yml

@@ -32,6 +32,8 @@ jobs:
           PYTHON_VERSION: 3.7
         python38:
           PYTHON_VERSION: 3.8
+        python39:
+          PYTHON_VERSION: 3.9
 
     steps:
     - template: .azure-pipelines/ci.yml
@@ -47,6 +49,8 @@ jobs:
           PYTHON_VERSION: 3.7
         python38:
           PYTHON_VERSION: 3.8
+        python39:
+          PYTHON_VERSION: 3.9
 
     steps:
     - template: .azure-pipelines/ci.yml
@@ -62,6 +66,8 @@ jobs:
           PYTHON_VERSION: 3.7
         python38:
           PYTHON_VERSION: 3.8
+        python39:
+          PYTHON_VERSION: 3.9
 
     steps:
     - template: .azure-pipelines/ci.yml