Update README.md

Author: rakibdevs

README.md

@@ -26,7 +26,7 @@ Install the package through [Composer](http://getcomposer.org).
 On the command line:
 
 ```
-composer require rakibdevs/openweather-laravel-api:'dev-master'
+composer require rakibdevs/openweather-laravel-api
 
 ```