update Travis Python version to 3.7

gronke · gronke · commit 28e715c0dbec · 2020-04-13T14:19:56.000Z
diff --git a/.travis.yml b/.travis.yml
@@ -1,6 +1,6 @@
 language: python
 python:
-  - "3.6"
+  - "3.7"
 sudo: false
 env:
   - MYPYPATH="$TRAVIS_BUILD_DIR/.travis/mypy-stubs"
