Add test for sign typed data with bytes

[rmeissner]

Added test that contain bytes for signing typed data.

The test values have been calculated with the following smart contract:

pragma solidity 0.4.24;

contract Test {
    
    function personData()
        public
        pure
        returns (bytes) 
    {
        bytes32 personSchemaHash = keccak256("Person(string name,address wallet)");
        return abi.encode(
            personSchemaHash,
            keccak256('Bob'),
            address(0xbBbBBBBbbBBBbbbBbbBbbbbBBbBbbbbBbBbbBBbB)
        );
    }
    
    function signData()
        public
        pure
        returns (bytes) 
    {
        bytes32 personSchemaHash = keccak256("Person(string name,address wallet)");
        return abi.encode(
            mailSchemaHash(),
            keccak256(
                abi.encode(
                    personSchemaHash,
                    keccak256('Cow'),
                    address(0xCD2a3d9F938E13CD947Ec05AbC7FE734Df8DD826)
                )
            ),
            keccak256(personData()),
            keccak256("Hello, Bob!"),
            keccak256(hex"25192142931f380985072cdd991e37f65cf8253ba7a0e675b54163a1d133b8ca")
        );
    }
    
    function signHash()
        public
        pure
        returns (bytes32) 
    {
        return keccak256(signData());
    }
    
    function sign()
        public
        pure
        returns (bytes32) 
    {
        return keccak256(abi.encodePacked(
            byte(0x19), 
            byte(1), 
            0xf2cee375fa42b42143804025fc449deafd50cc031ca257e0b194a650a912090f, 
            signHash()
        ));
    }
    
    
    function mailSchemaHash() 
        public
        pure
        returns (bytes32) 
    {
        return keccak256("Mail(Person from,Person to,string contents,bytes payload)Person(string name,address wallet)");
    }
}

[rmeissner]

would it be possible to confirm these test vectors and merge them?

[Gudahtt]

Thanks for the contribution @rmeissner ! Unfortunately we left this unreviewed for too long so it had gone quite stale. I've rebased this and updated it to match our current test style in this PR: #146, which can supersede this PR. I'll try to get it reviewed and merged ASAP.