let witness_script = Address::p2pkh(&::bitcoin::PublicKey{compressed: true, key: remotepubkey}, Network::Testnet).script_pubkey();
let sighash = Message::from_slice(&bip143::SighashComponents::new(&spend_tx).sighash_all(&spend_tx.input[0], &witness_script, output.value)[..]).unwrap();
let witness_script = Address::p2pkh(&::bitcoin::PublicKey{compressed: true, key: remotepubkey}, Network::Testnet).script_pubkey();
let sighash = Message::from_slice(&bip143::SighashComponents::new(&spend_tx).sighash_all(&spend_tx.input[0], &witness_script, output.value)[..]).unwrap();