- add comments to hashes shim
- remove .catch from callback condition
- derive SignerError from EthersError instead of ProviderError. This allows Providers and Signers to be separate, as Ledger does it, to isolate functionality. Some signer functions now raise both ProviderError and SignerError
- Update reverts to check for SignerError
- Update ERC-20 method comment
- signer procs raise SignerError, provider procs raise ProviderError
- WalletError now inherits from SignerError
- move wallet module under signers
- create jsonrpo moudle under signers
- bump nim-json-rpc for null-handling fixes
- All jsonrpc provider tests passing, still need to fix others
