events: Add new-test-result event

The event is logged when patchwork receives new test result for series
revision or for a patch.

Signed-off-by: Arkadiusz Hiler <arkadiusz.hiler@intel.com>
2 jobs for new-test-result-event in 1 minute and 15 seconds (queued for 1 second)
Status Name Job ID Coverage
  Test
passed test #1320752

00:01:15

canceled test #1320750

00:00:37