Updates the README.md (#591)

This change adds Icepay Payments to the list of packages.

Author: kiettran

README.md

@@ -160,6 +160,7 @@ Gateway | 2.x | 3.x | Composer Package | Maintainer
 [GVP (Garanti)](https://github.com/yasinkuyu/omnipay-gvp) | ✓ | - | yasinkuyu/omnipay-gvp | [Yasin Kuyu](https://github.com/yasinkuyu)
 [GVP (Garanti)](https://github.com/emr/omnipay-gvp) | - | ✓ | emr/omnipay-gvp | [Emre Akinci](https://github.com/emr)
 [Helcim](https://github.com/academe/omnipay-helcim) | ✓ | - | academe/omnipay-helcim | [Jason Judge](https://github.com/judgej)
+[Icepay Payments](https://github.com/superbrave/omnipay-icepay-payments) | - | ✓ | superbrave/omnipay-icepay-payments | [SuperBrave](https://github.com/superbrave)
 [iDram](https://github.com/ptuchik/omnipay-idram) | - | ✓ | ptuchik/omnipay-idram | [Avik Aghajanyan](https://github.com/ptuchik)
 [iDeal](https://github.com/deniztezcan/omnipay-ideal) | - | ✓ | deniztezcan/omnipay-ideal | [Deniz Tezcan](https://github.com/deniztezcan)
 [iPay88](https://github.com/dilab/omnipay-ipay88) | ✓ | ✓ | dilab/omnipay-ipay88 | [Xu Ding](https://github.com/dilab)