travis: bump dist to bionic

sebastinas · sebastinas · commit a546f4694e28 · 2020-10-11T14:38:10.000+02:00
diff --git a/.travis.yml b/.travis.yml
@@ -1,6 +1,6 @@
 language: python
 sudo: false
-dist: xenial
+dist: bionic
 
 python:
     - "2.7"
