Merge pull request #3988 from wp-cli/3728-super-admin-command

Abstract `wp super-admin` to wp-cli/super-admin-command

Author: danielbachhuber

composer.json

@@ -52,6 +52,7 @@
 		"wp-cli/entity-command": "^1.0",
 		"wp-cli/extension-command": "^1.0",
 		"wp-cli/config-command": "^1.0",
+		"wp-cli/super-admin-command": "^1.0",
 		"wp-cli/scaffold-command": "^1.0"
 	},
 	"require-dev": {