FIX Starting xvfb as a service to avoid travis failures

NelleV · NelleV · commit 252b95a85df4 · 2019-01-17T20:46:03.000-08:00
diff --git a/.travis.yml b/.travis.yml
@@ -3,6 +3,9 @@ language: python
 dist: xenial
 sudo: false
 
+services:
+  - xvfb
+
 branches:
   except:
   - /^auto-backport-of-pr-\d*/
