Add Python 3.7~3.9-dev to Travis.

Flameeyes · Flameeyes · commit 09feac3f3e9d · 2020-04-17T20:12:08.000+01:00
diff --git a/.travis.yml b/.travis.yml
@@ -6,7 +6,9 @@ python:
   - 3.4
   - 3.5
   - 3.6
-  # - 3.7
+  - 3.7
+  - 3.8
+  - 3.9-dev
 
 install: pip install tox-travis
 

-Original file line number
+Diff line change
   - 3.4
   - 3.5
   - 3.6
 -  # - 3.7
 +  - 3.7
 +  - 3.8
 +  - 3.9-dev
 install: pip install tox-travis