Update issues link in README.md

Author: danakatz

README.md

@@ -44,7 +44,7 @@ All tests are integration tests. Integration tests make API calls to Braintree a
 
 ## Help
 
- * Found a bug? Have a suggestion for improvement? Want to tell us we're awesome? [Submit an issue](https://github.com/braintree/braintree_rails_example/issues)
+ * Found a bug? Have a suggestion for improvement? Want to tell us we're awesome? [Submit an issue](https://github.com/braintree/braintree_php_example/issues)
  * Trouble with your integration? Contact [Braintree Support](https://support.braintreepayments.com/) / [email protected]
  * Want to contribute? [Submit a pull request](https://help.github.com/articles/creating-a-pull-request)