Update README.md

Author: Leonid74

README.md

@@ -9,7 +9,7 @@ API Documentation [https://sendpulse.com/api](https://sendpulse.com/api)
 Via Composer:
 
 ```bash
-composer require sendpulse/rest-api
+composer require Leonid74/sendpulse-rest-api-php
 ```
 
 ### Usage