try to fix '__subclasses__' of 'type' object error

javierluraschi · javierluraschi · commit a3cf2b676db5 · 2019-10-21T15:21:07.000-07:00
diff --git a/.travis.yml b/.travis.yml
@@ -65,7 +65,7 @@ matrix:
           sources:
             - deadsnakes
           packages:
-            - python3
+            - python3.8
             - python3-pip
 os:
   - linux
