Client-server communication.

[benkarstad]

Devise and implement a system by which a server can receive connections and communicate state information to client machines and vice-versa.
The connection must be:

• Low-latency

  Updates between devices must be responsive and fast to limit confusion due to multiple clients concurrently modifying state

• Continuous

  Systems like REST are unideal, as a server must be able to update client state at any time.
  A continuous connection helps to ensure that all clients' states are synchronized at all times.