elastic_recheck/tests/functional/test_gerrit_comment.py tests no longer work

These test cases are not gated and seem to have bit rot. When run, they fail with the following stack trace:

Error
_StringException: Traceback (most recent call last):
  File "/home/asselin/git/elastic-recheck/elastic_recheck/tests/functional/test_gerrit_comment.py", line 42, in test_bug_found
    self.stream.leave_comment(project, commit_id, bug_numbers)
  File "/home/asselin/git/elastic-recheck/elastic_recheck/elasticRecheck.py", line 339, in leave_comment
    if event.get_all_bugs():
AttributeError: 'str' object has no attribute 'get_all_bugs'