* Tests: Replace YAML tests with ESTestRestCase to be able to wait for events
The YAML tests did not have any possibility to wait for the watches to
be created. A hard ten second timeout was used, that could not be
aborted, by simulating a sleep when waiting for a number of nodes that
never occured in the cluster.
This commit replaces those waiting YAML tests with ESRestTestCases, that
use `assertBusy()` to exit early once the watches have been added. Also
this increases the wait time if needed, as these tests tend to fail on
CI.
relates elastic/x-pack-elasticsearch#3217
Original commit: elastic/x-pack-elasticsearch@74b9945d88
Created a smoke-test-monitoring-with-watcher project that runs REST
tests with watcher enabled to ensure that the proper watcher are
installed either when the local or the HTTP exporter are set up.
Also removed two more watcher imports in the tests.
Relates elastic/x-pack-elasticsearch#2925
Original commit: elastic/x-pack-elasticsearch@0a9abc3185
Alexander Reelsen