tests: remove unused imports

Author: dkropachev

tests/unit/io/test_twistedreactor.py

@@ -26,7 +26,7 @@
     twistedreactor = TwistedConnection = ConnectionDone = ConnectionLost = None  # NOQA
 
 
-from cassandra.connection import Connection, ConnectionShutdown, _Frame
+from cassandra.connection import ConnectionShutdown, _Frame
 from cassandra.protocol import ReadyMessage
 
 from tests.unit.io.utils import TimerTestMixin

tests/unit/test_cluster.py

@@ -19,7 +19,7 @@
 from threading import Event, Lock, RLock, Thread
 from types import SimpleNamespace
 
-from unittest.mock import call, patch, Mock
+from unittest.mock import patch, Mock
 import uuid
 
 from cassandra import ConsistencyLevel, DriverException, Timeout, Unavailable, RequestExecutionException, ReadTimeout, WriteTimeout, CoordinationFailure, ReadFailure, WriteFailure, FunctionFailure, AlreadyExists,\