Added Strakpay (Crypto payment) payment gateway (#634)

Author: starkpay

README.md

@@ -257,6 +257,7 @@ Gateway | 2.x | 3.x | Composer Package | Maintainer
 [Sofort](https://github.com/aimeoscom/omnipay-sofort) | ✓ | - | aimeoscom/omnipay-sofort | [Aimeos GmbH](https://github.com/aimeoscom)
 [Spreedly](https://github.com/gregoriohc/omnipay-spreedly) | ✓ | - | gregoriohc/omnipay-spreedly | [Gregorio Hernández Caso](https://github.com/gregoriohc)
 [Square](https://github.com/Transportersio/omnipay-square) | ✓ | - | transportersio/omnipay-square | [Transporters.io](https://github.com/Transportersio)
+[Starkpay](https://github.com/starkpay/omnipay) | ✓ | ✓ | starkpay/omnipay | [Starkpay](https://github.com/starkpay)
 [Stripe](https://github.com/thephpleague/omnipay-stripe) | ✓ | ✓ | omnipay/stripe | [Del](https://github.com/delatbabel)
 [TargetPay](https://github.com/thephpleague/omnipay-targetpay) | ✓ | - | omnipay/targetpay | [Alexander Deruwe](https://github.com/aderuwe)
 [TatraBank](https://github.com/bileto/omnipay-tatrabank) | ✓ | - | omnipay-tatrabank |