Added composer v1 as dev dependency

Author: Jonathan Guo

composer.json

@@ -22,11 +22,12 @@
     "yiisoft/yii2": "^2.0.13"
   },
   "require-dev": {
-    "phpunit/phpunit": "^8.4.0"
+    "phpunit/phpunit": "^8.4.0",
+    "composer/composer": "^1.6.0"
   },
   "autoload": {
     "psr-4": {
       "webtoolsnz\\helpers\\": "src"
     }
   }
-}
+}