Check if this fixes travis build for 3.10

Author: mpcabd

.travis.yml

@@ -4,22 +4,22 @@ install:
   - pip install -e .
 matrix:
   include:
-    - python: 2.7
+    - python: "2.7"
       env:
        - TOX_ENV=py27
-    - python: 3.6
+    - python: "3.6"
       env:
         - TOX_ENV=py36
-    - python: 3.7
+    - python: "3.7"
       env:
         - TOX_ENV=py37
-    - python: 3.8
+    - python: "3.8"
       env:
         - TOX_ENV=py38
-    - python: 3.9
+    - python: "3.9"
       env:
         - TOX_ENV=py39
-    - python: 3.10
+    - python: "3.10"
       env:
         - TOX_ENV=py310
 script: tox -e $TOX_ENV