Clearly separate Unit Tests from Integration Tests

[gakonst]

Is your feature request related to a problem? Please describe.

In our tests we frequently call out to 3rd party providers: Infura, Etherscan, Alchemy, various Gas Oracles and so on. These tests are mixed inside the unit test code. Sometimes these tests fail for 3rd party reasons (rate limiting, service down, 2 PRs opened at the same time causing nonce-reuse etc.) and they can cause confusion.

Describe the solution you'd like

It'd be nice if we could:

1. Refactor all tests that use the local blockchain (Ganache/Geth locally spun up) w/o any 3rd party deps to be unit tests
2. Refactor all tests that use 3rd party providers to be integration tests (i.e. under a crate's test/ dir)
3. (Maybe) Create a separate CI pipeline which ONLY runs the integration tests and make the current CI pipeline only run the unit tests