Use latest distirbution of Ubuntu 16.04 xenial

satoryu · satoryu · commit b66db3db2068 · 2021-01-01T17:04:05.000+09:00
diff --git a/.travis.yml b/.travis.yml
@@ -1,6 +1,5 @@
 language: ruby
-dist: trusty
-sudo: false
+dist: xenial
 rvm:
   - 2.5
   - 2.6
