Added StorageKey implementation for Signature (#738)
Added StorageKey implementation for Signature (#738)

* Added StorageKey implementation for Signature
Added macro for crypto types
Updated Hash and PublicKey to implement StorageKey via macro

alekseysidorov/exonum,alekseysidorov/exonum,exonum/exonum,exonum/exonum,exonum/exonum,alekseysidorov/exonum,exonum/exonum,alekseysidorov/exonum