Test the failure detector

[rosalogia]

Summary

The failure detection component is now mostly implemented, but we have very little idea as to whether or not it actually does its job.
We can use this issue thread to brainstorm and propose scenarios we can use to test the failure detector.

Relevant Documentation and Links

• Location of failure detector implementation in the codebase (note that type definitions are at the top of the file)
• SWIM paper, detailing the theory behind the implementation

Related PRs and Issues:

• Integrate failure detector into client #21
• swim(initSwimProtocol): Failure detector module from SWIM protocol #5
• Mutate client's peer list when updating peer state in failure detector #25