Reading List- https://medium.com/coinmonks/build-a-smart-contract-that-transfers-erc20-token-from-your-wallet-to-other-addresses-or-erc20-ee8dc35f40f6 https://medium.com/taipei-ethereum-meetup/smart-contract-unit-testing-use-erc20-token-contract-as-an-example-d150c2700834