check and fix all urls

Coinkite, Coinpunk, Hive and QuickCoin are closed. Also fixed Dark Wallet URL.

README.md

@@ -121,15 +121,11 @@ If you have a use case that you feel could be listed here, please [ask for it](h
 - [Blockchain.info](https://blockchain.info/wallet)
 - [Blocktrail](https://www.blocktrail.com/)
 - [Brainwallet](https://brainwallet.io/)
-- [Coinkite](https://coinkite.com)
-- [Coinpunk](https://coinpunk.com)
-- [Dark Wallet](https://darkwallet.unsystem.net)
+- [Dark Wallet](https://www.darkwallet.is/)
 - [DecentralBank](http://decentralbank.com/)
 - [Dogechain Wallet](https://dogechain.info)
 - [EI8HT Wallet](http://ei8.ht/)
 - [GreenAddress](https://greenaddress.it)
-- [Hive Wallet](https://www.hivewallet.com)
-- [QuickCoin](https://wallet.quickcoin.co)
 - [Robocoin](https://wallet.robocoin.com)
 - [Skyhook ATM](http://projectskyhook.com)