Also lint PHP files as part of CI build

Author: manicki

.travis.yml

@@ -6,9 +6,11 @@ php:
 before_script:
   - nvm install 4
   - npm install
+  - composer install
 
 script:
   - npm test
+  - composer test
 
 notifications:
   irc:

DataValuesJavaScript.php

@@ -14,6 +14,10 @@
 	require_once __DIR__ . '/vendor/autoload.php';
 }
 
+if ( !defined( 'MEDIAWIKI' ) ) {
+	return 1;
+}
+
 $GLOBALS['wgExtensionCredits']['datavalues'][] = [
 	'path' => __DIR__,
 	'name' => 'DataValues JavaScript',