ShardedClusterFixture tries to access never started mongos

 [2018/07/27 19:49:24.037] [executor:js_test] 2018-07-27T19:49:15.765+0000 Encountered an error while tearing down ShardedClusterFixture (Job #1).

 [2018/07/27 19:49:24.037] Traceback (most recent call last):

 [2018/07/27 19:49:24.037]   File "/data/mci/1139f947d37beb2b472c84950f7b8076/src/buildscripts/resmokelib/testing/executor.py", line 213, in _teardown_fixtures

 [2018/07/27 19:49:24.037]     if not job.fixture.teardown(finished=True):

 [2018/07/27 19:49:24.037]   File "/data/mci/1139f947d37beb2b472c84950f7b8076/src/buildscripts/resmokelib/testing/fixtures/interface.py", line 67, in teardown

 [2018/07/27 19:49:24.037]     return self._do_teardown()

 [2018/07/27 19:49:24.037]   File "/data/mci/1139f947d37beb2b472c84950f7b8076/src/buildscripts/resmokelib/testing/fixtures/shardedcluster.py", line 142, in _do_teardown

 [2018/07/27 19:49:24.037]     self._stop_balancer()

 [2018/07/27 19:49:24.037]   File "/data/mci/1139f947d37beb2b472c84950f7b8076/src/buildscripts/resmokelib/testing/fixtures/shardedcluster.py", line 128, in _stop_balancer

 [2018/07/27 19:49:24.038]     self._auth_to_db(client)

 [2018/07/27 19:49:24.038]   File "/data/mci/1139f947d37beb2b472c84950f7b8076/src/buildscripts/resmokelib/testing/fixtures/shardedcluster.py", line 123, in _auth_to_db

 [2018/07/27 19:49:24.038]     mechanism=self.auth_options["authenticationMechanism"])

 [2018/07/27 19:49:24.038]   File "/opt/mongodbtoolchain/v2/lib/python2.7/site-packages/pymongo/database.py", line 1075, in authenticate

 [2018/07/27 19:49:24.038]     connect=True)

 [2018/07/27 19:49:24.038]   File "/opt/mongodbtoolchain/v2/lib/python2.7/site-packages/pymongo/mongo_client.py", line 542, in _cache_credentials

 [2018/07/27 19:49:24.038]     writable_preferred_server_selector)

 [2018/07/27 19:49:24.038]   File "/opt/mongodbtoolchain/v2/lib/python2.7/site-packages/pymongo/topology.py", line 214, in select_server

 [2018/07/27 19:49:24.038]     address))

 [2018/07/27 19:49:24.038]   File "/opt/mongodbtoolchain/v2/lib/python2.7/site-packages/pymongo/topology.py", line 189, in select_servers

 [2018/07/27 19:49:24.038]     self._error_message(selector))

 [2018/07/27 19:49:24.038] ServerSelectionTimeoutError: localhost:27017: [Errno 111] Connection refused