Add parameterised tests for different ERC20 flavors

[jmonteer]

Description: Tests should be parameterised with different tokens.

examples: USDT has special cases around not complying exactly with ERC20 USDC 6 decimals WBTC 8 decimals some other with 2 decimals

vault should be 100% compatible with at least: USDC, USDT, DAI, WBTC, WETH and YFI

Dependencies: NA

Acceptance criteria:

• tests running for different flavors of ERC20 tokens

Payment Trigger: PR is merged Category: DEV Level: 2

[pandadefi]

This is something done on the v2 version and can be copy and pasted. https://github.com/yearn/yearn-vaults/blob/master/tests/functional/conftest.py#L35 Side note, you might want to introduce parallel ci testing when introducing these changes.

[bufander]

I've given some research. Used xdist and run tests with ape test -n auto. Unfortunately it doesn't work.

any idea from you guys?

[jmonteer]

after convo: this took very long and was very well worth it: moved to lvl 2