Marked vdbelt/oppwa as 3.x compatible

Author: vdbelt

README.md

@@ -166,7 +166,7 @@ Gateway | 2.x | 3.x | Composer Package | Maintainer
 [Network Merchants Inc. (NMI)](https://github.com/mfauveau/omnipay-nmi) | ✓ | - | mfauveau/omnipay-nmi | [Matthieu Fauveau](https://github.com/mfauveau)
 [Nocks](https://github.com/nocksapp/checkout-omnipay) | ✓ | - | nocksapp/omnipay-nocks | [Nocks](https://github.com/nocksapp)
 [OnePay](https://github.com/dilab/omnipay-onepay) | ✓ | ✓ | dilab/omnipay-onepay | [Xu Ding](https://github.com/dilab)
-[Oppwa](https://github.com/vdbelt/omnipay-oppwa) | ✓ | - | vdbelt/omnipay-oppwa | [Martin van de Belt](https://github.com/vdbelt)
+[Oppwa](https://github.com/vdbelt/omnipay-oppwa) | ✓ | ✓ | vdbelt/omnipay-oppwa | [Martin van de Belt](https://github.com/vdbelt)
 [Payoo](https://github.com/dilab/omnipay-payoo) | ✓ | ✓ | dilab/omnipay-payoo | [Xu Ding](https://github.com/dilab)
 [Pacnet](https://github.com/mfauveau/omnipay-pacnet) | ✓ | - | mfauveau/omnipay-pacnet | [Matthieu Fauveau](https://github.com/mfauveau)
 [Pagar.me](https://github.com/descubraomundo/omnipay-pagarme) | ✓ | - | descubraomundo/omnipay-pagarme | [Descubra o Mundo](https://github.com/descubraomundo)