Adds native segwit script types

[mariorz]

BtcdClient.decodeRawTransaction raises an IllegalArgumentException on parsing native segwit script types: witness_v0_keyhash, witness_v0_scripthash

e.g.

java.lang.IllegalArgumentException: Error #1001010: Expected the argument to be a valid 'bitcoind' script type, but was invalid/unsupported instead. 2017-08-29 03:59:06.839431500 at com.neemre.btcdcli4j.core.domain.enums.ScriptTypes.forName(ScriptTypes.java:43)

This patch adds the missing enums to fix.