Rate limiter middleware

[crookse]

Summary

What:

Add rate limiter for app-level rate limiting. Inspiration to come from:

• https://github.com/animir/node-rate-limiter-flexible
• https://github.com/nfriedly/express-rate-limit

Why:

Adding a rate limiter middleware is a must. Even though you can apply them at web server level, not everyone has access to this in their use cases (AWS Serveless, Heroku Apps, Google Cloud Apps, etc).

Acceptance Criteria

Below is a list of tasks that must be completed before this issue can be closed.

• Write middleware
• Write documentation
• Write unit tests
• Write integration tests