Bump composer/installers

Author: unfulvio

composer.json

@@ -16,7 +16,7 @@
   ],
 	"require": {
 		"php": ">=5.4.0",
-		"composer/installers": "^1.0",
+		"composer/installers": "~1.0",
     "nekojira/wp-requirements": "^1.4",
 		"php-console/php-console": "~3.1",
     "xrstf/composer-php52": "1.*"