Update require version number to latest tag

Author: Meyyappan Velayutham

README.md

@@ -25,7 +25,7 @@ or edit the `composer.json`
 
 ```
 "require": {
-    "linkstreet/laravel-sms": "^3.0"
+    "linkstreet/laravel-sms": "^4.0"
 }
 ```
 
@@ -77,4 +77,4 @@ The MIT License (MIT). Please see [License File](LICENSE) for more information.
 [link-codecov]: https://codecov.io/github/linkstreet/laravel-sms?branch=master
 [link-packagist]: https://packagist.org/packages/linkstreet/laravel-sms
 [link-downloads]: https://packagist.org/packages/linkstreet/laravel-sms
-[link-license]: LICENSE
+[link-license]: LICENSE