Zpywallet

Support Segwit transaction signing.

**Full Changelog**: https://github.com/ZenulAbidin/zpywallet/compare/v0.5.0...v0.5.1

This is a major release, with many breaking changes that aren't compatible with previous versions. However, there are still a few major bugs in the library, so it will not get a major version number yet:

- Create address classes for searching for balances
- Create functions for creating and broadcasting transactions
- Add stock, public nodes
- Embed base58, bech32, mnemonic functions and remove external library dependencies
- Create `Wallet` class which intertwines all functionality together, can be serialized using protobuf

Major updates with key generation:

- Public and private keys are now generated using `coincurve`, which itself uses libsecp256k1- previously they were generated with the extremely insecure `ecdsa` library leftover from PyWallet. Coincurve has wheels available for all major platforms so you won't need build tools installed to use this module.
- Drop support for all Python < 3.8 because of `coincurve` dependency.
- `PublicKey` and `PrivateKey` classes have been heavily refactored.
- The redundant `HDKey`/`HDPrivateKey`/`HDPublicKey` classes have been removed - use `Wallet` directly instead. `Wallet` class has absorbed the HD wallet generation methods of these classes which it previously did not have.

This is a minor release, which exports an easier `create_wallet` function for creating Wallet objects, and renames the original `create_wallet` to `create_wallet_json`.

This release advances ZPyWallet to a beta state and fixes several bugs:

- Fixes the incorrect child HD keys caused by improper generation of the seed bytes before hashing it with HMAC: https://github.com/ranaroussi/pywallet/issues/14
- Bundle a ripemd160 function as a result of `hashlib('ripemd160')` being disabled for Python 3.10+: https://stackoverflow.com/questions/72409563/unsupported-hash-type-ripemd160-with-hashlib-in-python/72508879#72508879
- `export_wif` function now generates the standard, uncompressed WIFs by default
- Miscellaneous class de-duplication and refactoring

This release fixes a bug related to key creation that is experienced if pygmp is installed.