Added (unofficial) PAYONE to README

Author: judgej

README.md

@@ -161,6 +161,7 @@ Gateway | Composer Package | Maintainer
 [PaymentWall](https://github.com/incube8/omnipay-paymentwall) | incube8/omnipay-paymentwall | [Del](https://github.com/delatbabel)
 [PayPal](https://github.com/thephpleague/omnipay-paypal) | omnipay/paypal | [Del](https://github.com/delatbabel)
 [PayPro](https://github.com/payproNL/omnipay-paypro) | paypronl/omnipay-paypro | [Fruitcake Studio](https://github.com/fruitcakestudio)
+[PAYONE](https://github.com/academe/omnipay-payone) | academe/omnipay-payone | [Jason Judge](https://github.com/judgej)
 [Paysafecard](https://github.com/dercoder/omnipay-paysafecard) | dercoder/omnipay-paysafecard | [Alexander Fedra](https://github.com/dercoder)
 [PayTrace](https://github.com/iddqdidkfa/omnipay-paytrace) | softcommerce/omnipay-paytrace | [Oleg Ilyushyn](https://github.com/iddqdidkfa)
 [PayU](https://github.com/efesaid/omnipay-payu) | omnipay/payu | [efesaid](https://github.com/efesaid)