Updated Angular ERC20 Wallet Example

Just updated the Example #ERC20 Token Payments Repository to support Approve for Address. This is particularly useful for granting allowance to a Smart Contract. #BUIDL

https://github.com/emmonspired/erc20-digital-signature-verify/issues/1

Originally mentioned in article: #Whitepaper and Demo: UX for #Authenticated & #Verified #ERC20 Payments Using MetaMask and #EthSigUtil

https://steemit.com/ethereum/@emmonspired/whitepaper-and-demo-ux-for-authenticated-and-verified-erc20-payments-using-metamask-and-ethsigutil