tests/integration: switch from unittest.skip to pytest.mark.skip

when we use `unittest.skip` on a test function and run via pytest,
we still collect the test and run the setup/teardown even the
test function would be skipped.

when running with cassandra we get into situations where create
cluster is also failing for all kind of reasons, which we don't
need that cluster.

tests/integration/standard/test_control_connection.py

@@ -17,7 +17,7 @@
 from cassandra import InvalidRequest
 
 import unittest
-
+import pytest
 
 from cassandra.protocol import ConfigurationException
 from tests.integration import use_singledc, PROTOCOL_VERSION, TestCluster, greaterthanorequalcass40, notdse
@@ -101,7 +101,7 @@ def test_get_control_connection_host(self):
         self.assertNotEqual(host, new_host)
 
     # TODO: enable after https://github.com/scylladb/python-driver/issues/121 is fixed
-    @unittest.skip('Fails on scylla due to the broadcast_rpc_port is None')
+    @pytest.mark.skip('Fails on scylla due to the broadcast_rpc_port is None')
     @notdse
     @greaterthanorequalcass40
     def test_control_connection_port_discovery(self):

tests/integration/standard/test_metadata.py

@@ -55,7 +55,7 @@ def setup_module():
 
 class HostMetaDataTests(BasicExistingKeyspaceUnitTestCase):
     # TODO: enable after https://github.com/scylladb/python-driver/issues/121 is fixed
-    @unittest.skip('Fails on scylla due to the broadcast_rpc_port is None')
+    @pytest.mark.skip('Fails on scylla due to the broadcast_rpc_port is None')
     @local
     def test_host_addresses(self):
         """

tests/integration/standard/test_single_interface.py

@@ -13,6 +13,7 @@
 # limitations under the License.
 
 import unittest
+import pytest
 
 from cassandra import ConsistencyLevel
 from cassandra.query import SimpleStatement
@@ -45,7 +46,7 @@ def tearDown(self):
             self.cluster.shutdown()
 
     # TODO: enable after https://github.com/scylladb/python-driver/issues/121 is fixed
-    @unittest.skip('Fails on scylla due to the broadcast_rpc_port is None')
+    @pytest.mark.skip('Fails on scylla due to the broadcast_rpc_port is None')
     def test_single_interface(self):
         """
         Test that we can connect to a multiple hosts bound to a single interface.