Some of the unit tests (specifically event tests for clients that test an event takes a certain amount of time) are quite flaky when running the tests in parallel.

Maybe mark them as flaky so they repeat if they fail up to a certain number of times?

I have also observed the java krpc.client.EventTest test failing in CI (which doesn't run in parallel). These event tests are flaky as they test how long the event takes (in seconds). We could either increase the tolerance on the time measurements, or retry the test a few times until it passes.

Related to #629

LIst of flaky tests:

• Java client:
  • krpc.client.EventTest
• Python client:
  • krpc.test.test_event.TestEvent.test_event_calback
  • krpc.test.test_event.TestEvent.test_event_remove_callback