Merge pull request bitcoin#672 from skywinder/patch-1

BIP 39: Аdd swift library with multi lang support

Author: luke-jr

bip-0039.mediawiki

@@ -165,6 +165,7 @@ Rust:
 Swift:
 * https://github.com/CikeQiu/CKMnemonic
 * https://github.com/yuzushioh/WalletKit
+* https://github.com/matter-labs/web3swift/blob/develop/Sources/web3swift/KeystoreManager/BIP39.swift
 
 C++:
 * https://github.com/libbitcoin/libbitcoin-system/blob/master/include/bitcoin/system/wallet/mnemonic.hpp