Read Write Sawtooth Web Service Wrapper

[djat]

Accept a post with a JSON payload for Account, Emission, Pledge that will wrap underlying sawtooth libraries to prepare a transaction and write it to sawtooth and return transaction ID and the sawtooth address.

Another single REST endpoint will receive a request with a sawtooth address as one of the parameters and return a JSON payload with the chain metadata for either of the asset types.

Future work and investigation will begin around the account/key/wallet management and security architecture.