Use neutron-lib portbindings api-def

This patch refactors networking-arista to use portbindings
from neutron-lib. For more details see [1].

NeutronLibImpact

[1] https://review.openstack.org/422210/

Change-Id: I947aea591451ac3feb710daeb2f5e8ac34f7c574

networking_arista/ml2/arista_ml2.py

@@ -19,6 +19,7 @@ import json
 import os
 import socket
 
+from neutron_lib.api.definitions import portbindings
 from neutron_lib import constants as n_const
 from oslo_config import cfg
 from oslo_log import log as logging
@@ -26,8 +27,6 @@ from oslo_utils import excutils
 import requests
 from six import add_metaclass
 
-from neutron.extensions import portbindings
-
 from networking_arista._i18n import _, _LI, _LW, _LE
 from networking_arista.common import db_lib
 from networking_arista.common import exceptions as arista_exc

networking_arista/ml2/mechanism_arista.py

@@ -15,12 +15,12 @@
 
 import threading
 
+from neutron_lib.api.definitions import portbindings
 from neutron_lib import constants as n_const
 from oslo_config import cfg
 from oslo_log import log as logging
 
 from neutron.common import constants as neutron_const
-from neutron.extensions import portbindings
 from neutron.plugins.common import constants as p_const
 from neutron.plugins.ml2.common import exceptions as ml2_exc
 from neutron.plugins.ml2 import driver_api

networking_arista/tests/unit/ml2/test_arista_mechanism_driver.py

@@ -18,11 +18,11 @@ import socket
 
 import mock
 from mock import patch
+from neutron_lib.api.definitions import portbindings
 from neutron_lib import constants as n_const
 from oslo_config import cfg
 
 import neutron.db.api as db
-from neutron.extensions import portbindings
 from neutron.plugins.ml2 import driver_api as api
 from neutron.tests import base
 from neutron.tests.unit import testlib_api

networking_arista/tests/unit/ml2/test_mechanism_arista.py

@@ -14,10 +14,10 @@
 # limitations under the License.
 
 import mock
+from neutron_lib.api.definitions import portbindings
 from neutron_lib import constants as n_const
 
 from neutron.common import constants as neutron_const
-from neutron.extensions import portbindings
 from neutron.plugins.ml2 import driver_api as api
 from neutron.tests.unit import testlib_api