Deduplicate ERC20 Token

[schemar]

Follow-up to OpenST/mosaic-contracts#728

For testing, all repositories should use ERC20 Token from openzeppelin's npm package instead of re-creating it themselves.

Some repositories require an ERC20 interface in order to call contracts from within tests and other things. For those cases, use a dependency on openzeppelin.

https://github.com/OpenZeppelin/openzeppelin-solidity/tree/master/contracts/token

[benjaminbollen]

is there an OpenZeppeling or by others implementation that we can use to deduplicate ?

[schemar]

https://github.com/OpenZeppelin/openzeppelin-solidity/tree/master/contracts/token