Cache pip for Travis builds

natanlao · natanlao · commit 60de67ff88bd · 2019-12-17T13:30:48.000-08:00
diff --git a/.travis.yml b/.travis.yml
@@ -1,6 +1,8 @@
 language: python
 dist: xenial  # for python3.7+ testing
 
+cache: pip
+
 python:
 - 3.6
 - 3.7
