* Strip erc20 package of legacy nonsense and add foundry basics
* Make foundry build
* Remove obsoleted test/UntransferrableDummyERC20Token.sol contract
* Remove obsoleted ERC20 lib variant contracts
* Remove obsoleted DummyMultipleReturnERC20Token and DummyNoReturnERC20Token contracts
* Move test contract to dedicated folder
and remove obsoleted TypeScript contract wrappers
* Remove src/interfaces/IEtherToken.sol only used in
v3 staking which is being obsoleted [skip ci]
* Add foundry test for token
* Migrate ZRX token tests to foundry
* Fix paths to erc20 contracts
* Remove obsoleted references
* Pin erc20-contracts package on treasury
* Ignore foundry imports in link checker
* Run only forge tests for erc20 contracts
* Remove DummyERC20Token and its dependencies
* Merge IERC20TokenV06 and IERC20TokenV08
into range pragma to cover solidity 0.6.5 to 0.8.x
* Merge IEtherTokenV06 and IEtherTokenV08
into range pragma to cover solidity 0.6.5 to 0.8.x
* Migrate weth9 tests to foundry
* Upload code coverage for erc20 package
* Update changelog
* Fix review comments
Co-authored-by: duncancmt <1207590+duncancmt@users.noreply.github.com>
---------
Co-authored-by: duncancmt <1207590+duncancmt@users.noreply.github.com>
