Test on PHP 7 in Travis

MediaWiki and Wikibase no longer support PHP 5.5.

Author: lucaswerkmeister

.travis.yml

@@ -4,7 +4,13 @@ matrix:
   fast_finish: true
   include:
     - env: DBTYPE=sqlite
-      php: 5.5
+      php: 7.0
+    - env: DBTYPE=sqlite
+      php: 7.1
+    - env: DBTYPE=sqlite
+      php: 7.2
+    - env: DBTYPE=mysql
+      php: 7.2
     - env: DBTYPE=mysql
       php: hhvm
     - env: DBTYPE=sqlite