Start testing on PHP 7.2

Author: duncan3dc

.travis.yml

@@ -4,6 +4,7 @@ php:
   - 5.6
   - 7.0
   - 7.1
+  - 7.2
 
 # This triggers builds to run on the new TravisCI infrastructure.
 # See: http://docs.travis-ci.com/user/workers/container-based-infrastructure/