Allow ypub keys (#12)
Allow ypub keys (#12)

* support for ypub keys

* ypub key fixed

* derive P2WPKH over P2SH segwit address

* Implement P2WPKH over P2SH address generation

prusnak/bip32utils,satoshilabs/bip32utils,prusnak/bip32utils,satoshilabs/bip32utils