add sha256 hash test case
add sha256 hash test case

BWallet/libbitcoin,libmetrocoin/libmetrocoin-consensus,libmetrocoin/libmetrocoin-consensus,Airbitz/libbitcoin,Airbitz/libbitcoin,GroestlCoin/libgroestlcoin,libtetcoin/libtetcoin-consensus,libtetcoin/libtetcoin-consensus,Airbitz/libbitcoin,swansontec/libbitcoin,GroestlCoin/libgroestlcoin,Airbitz/libbitcoin,swansontec/libbitcoin,libmetrocoin/libmetrocoin-consensus,BWallet/libbitcoin,BWallet/libbitcoin,libmetrocoin/libmetrocoin-consensus,libtetcoin/libtetcoin-consensus,GroestlCoin/libgroestlcoin,libtetcoin/libtetcoin-consensus,BWallet/libbitcoin,swansontec/libbitcoin,libmetrocoin/libmetrocoin-consensus,swansontec/libbitcoin,GroestlCoin/libgroestlcoin,libtetcoin/libtetcoin-consensus