Tachyon system/serverStats

[L-e-x-o-n]

Completes #561

[geekingfrog]

Some tiny comments.
But you are missing a test for the feature.
You should add a function server_stats in Support.Tachyon that sends the message and wait for the response. There are plenty of other function doing similar things, list_queues! for example.

Then you should create a new file under test/teiserver_web/tachyon/system_test.exs, that use TeiserverWeb.ConnCase.

Then, you can follow the same pattern as the pairing tests to have several user connected.
You can then test that the request returns the correct response, then disconnect a client and try again to see the count updated.
Keep in mind that you’ll need the response schema in the repo as well since the end to end tests are validating the response against the expected schema.