S2699 should support Awaitility test framework

The current implementation of RSPEC-2699 does not support Awaitility framework, used to test asynchronous operations.

Note that when this ticket is implemented, the whitelist of supported framework in RSPEC-2699 should also be updated (and maybe the list order alphabetically).

From the documentation of Awaitility, it seems that only a call to .until(condition); marks the end of the definition of an assertion. Therefore, the rule should be extended to only consider a test having an assertions if such call is done, and not only a call to await()

Example of code asserting nothing:

await().atMost(TIMEOUT, TimeUnit.SECONDS);

Example of valid assertion using awaitility:

await().atMost(TIMEOUT, TimeUnit.SECONDS).until(newUserIsAdded());