Include python 3.7 for travis

Nick Joyce · Nick Joyce · commit b1c0b1bbcfe2 · 2019-06-20T14:14:37.000+01:00
diff --git a/.travis.yml b/.travis.yml
@@ -1,7 +1,7 @@
 language: python
 python:
   - "2.7"
-  - "3.6"
+  - "3.7"
 
 install:
   - pip install -r requirements_dev.txt
