Add paysafecard for omnipay v3 (#602)

Author: roryy

README.md

@@ -217,6 +217,7 @@ Gateway | 2.x | 3.x | Composer Package | Maintainer
 [PayPro](https://github.com/payproNL/omnipay-paypro) | ✓ | - | paypronl/omnipay-paypro | [Fruitcake](https://github.com/fruitcake)
 [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)
+[Paysafecard](https://github.com/worldstream-labs/omnipay-paysafecard) | - | ✓ | worldstream-labs/omnipay-paysafecard | [Worldstream](https://github.com/worldstream-labs)
 [Paysera](https://github.com/povils/omnipay-paysera) | ✓ | - | povils/omnipay-paysera | [Povils](https://github.com/povils)
 [Paysera](https://github.com/semyonchetvertnyh/omnipay-paysera) | - | ✓ | semyonchetvertnyh/omnipay-paysera | [Semyon Chetvertnyh](https://github.com/semyonchetvertnyh)
 [PaySimple](https://github.com/dranes/omnipay-paysimple) | ✓ | - | dranes/omnipay-paysimple | [Dranes](https://github.com/dranes)