It used a timer to sleep.
But time also goes on when doing other things, so depending on hardware, the timings could be off.
I slightly changed the tests so we still test what we functionally want.
Instead of waiting until the cache expires I now have a function to expire the test and use that.
That means we're not testing any more if the cache really expires after a certain amount of time,
but that's the responsability of the dependency imo, so shouldn't be a problem.
I also changed `Pleroma.Web.Endpoint, :http, :ip` to `127.0.0.1` because that's the setting people typically have,
and I see no reason to do it differently.
Especially since it's an exernal ip, which may come over as weird or suspicious to people.
lain