Upgrade TravisCI distro to bionic

jcoyne · cbeer · commit 34e30799ade3 · 2019-09-11T07:10:10.000-07:00
diff --git a/.travis.yml b/.travis.yml
@@ -1,4 +1,4 @@
-dist: xenial
+dist: bionic
 addons:
   chrome: stable
 language: ruby
