Set in constructor of BaseParaSwapSellAdapter and validates before swap.
Created mock registry that only validates one address.
Changed the test fixtures to accomodate registry and added two new tests.
Updated deployment script.
Registry address left as a placeholder in package.json since not known yet.
Fixes MixBytes Warning 1.
Complete with unit tests (using a mock AugustusSwapper contract).
Has similar functionality/tests as for existing Uniswap adapter.
Fixed a couple bugs in tests for Uniswap adapters.
