Vanchi/better presence tests


Step 1 for presence rewrite.

Shorten presence test timeout
Restructure unit tests

/cc @zendesk/zendesk-radar


### Steps to merge
 - [ ] :+1: of the team

### References
 - Jira link: 

### Risks
 - None
I think these should compare the entire structure of the message, so that breaking changes will cause this test to fail instead of being ignored.
```
asert.deepEqual(remote[0], {
  online: false,
  userId: 1,
  clientId: client.id,
})
```