Enable php-http/discovery plugin (#107)

Enable php-http/discovery plugin

Author: Keelan Fadden-Hopper

composer.json

@@ -43,7 +43,8 @@
             "cweagans/composer-patches": true,
             "drupal/core-composer-scaffold": true,
             "drupal/core-project-message": true,
-            "dealerdirect/phpcodesniffer-composer-installer": true
+            "dealerdirect/phpcodesniffer-composer-installer": true,
+            "php-http/discovery": true
         }
     },
     "extra": {