Fix the valid timestamp range not being wide enough.
The authentication will be considered valid if the timestamp is within five minutes of the current time.
Merge branch 'issues/26'
When upserting the user UUID check if we have the key, instead of if it is empty.

Some formatting changes.
Fix test error while upserting the user UUID caused by incorrectly setting up the fakequery result.

Closes #28
Merge remote-tracking branch 'origin/master' into angular

Conflicts:
	src/Authentication.php