Middleware-level testing of rate limits and auth tokens

[travis]

We should add some middleware or service-level tests to ensure that the new rate limit and auth token functionality doesn't regress.

We have some short term goals and some medium term ones - it would be nice to at least sketch out some of the medium term goals in testing, even if we keep those tests disabled for now. For example, we definitely need a test that shows that once a user has created an auth token they are able to access a resource with no rate limit, but we should probably also have one that shows that an invalid delegation should not result in access to a resource, but our current iteration may not have any concept of delegations, instead simply tracking auth tokens in a table we control.

Put another way, I'd like this issue to capture putting some integration testing into place now and laying some rails for the evolution of this project toward a more decentralized design.

[fforbeck]

• Unit Tests for the Rate Limiter added here -> feat: rate limiter + unit tests + readme freeway#115

[fforbeck]

• Integration Tests Setup added here -> chore: integration tests setup freeway#116

[fforbeck]

Integration & Unit tests setup implemented and added as part of the GitHub Test workflow.
We still don't have the concept of Delegations in the Freeway project, so the tests are considering simple Bearer Authentication tokens to test the rate-limit strategy.