Merge pull request #227 from wp-cli/bump-travis-server-to-xenial

Bump Travis CI OS from `trusty` to `xenial`

Author: schlessera

.travis.yml

@@ -1,9 +1,12 @@
 os: linux
-dist: trusty
+dist: xenial
 
 language: php
 php: 7.4
 
+services:
+  - mysql
+
 notifications:
   email:
     on_success: never
@@ -71,6 +74,7 @@ jobs:
     - stage: test
       php: 5.6
       env: WP_VERSION=3.7.11
+      dist: trusty
     - stage: test
       php: 5.6
       env: WP_VERSION=trunk