Add function to transfer ownership

[arjundashrath]

@workwithamit add a function in the contract called transferToken. This function takes an address and tokenId as input and appends that address to the ownershipHistory array of the struct object having that tokenId

[arjundashrath]

@workwithamit I made a few changes to the code and added the transferToken function.

digital-passport/digitalPassport.sol

Line 33 in 3053559

function transferToken(uint256 _tokenId, address _newOwner) public {

The way I have added the new owner to the array is more gas efficient. Now, you need to similarly update the timestamp as well in the same function, in the similar way