Bring Python current in Travis

Author: gliptak

.travis.yml

@@ -17,13 +17,14 @@ script:
 
 jobs:
   allow_failures:
-    - python: 3.9-dev
+    - python: 3.10-dev
     - python: pypy3
   include:
     - python: 3.6
     - python: 3.7
     - python: 3.8
-    - python: 3.9-dev
+    - python: 3.9
+    - python: 3.10-dev
     - python: pypy3
 
     - stage: Expose env-var information