5901d35095 Add push_p2wpkh function on Witness (Tobin C. Harding)
8cd409d561 Deprecate push_bitcoin_signature (Tobin C. Harding)
Pull request description:
In order to create the witness to spend p2wpkh output one must create a `Witness` that includes the signature and the pubkey, we should have a function for this.
## Notes
The PR originally added a `push_p2wphk` method, this is now instead a constrcutor `Witness:p2wpkh` (after review discussion below).
- Patch 1 changes `push_bitcoin_signature` to take an `ecdsa::Sigtnture` instead of an `ecdsa::SerializedSignature`
- Patch 2 takes a `secp256k1::PublicKey` removing the need for an error path (discussed below).
ACKs for top commit:
sanket1729:
ACK 5901d35095
apoelstra:
ACK 5901d35095
Tree-SHA512: 646014d97daafbf0909106d8990debaf481ac6f3578f0ddf232d739c3e2d55ae1d0275abe5a4a1db1c5c192c8c5f0b5546fc65aac37b91a3729db881c5ad3dec