consume neutron-lib callbacks

The callback system in neutron has moved to neutron-lib and hence
consumers need to follow suit.
See Ib6baee2aaeb044aaba42a97b35900d75dd43021f for more details.

Change-Id: Ibe6ec3bf9c4a97ab2e0aa9747272d885fca2936b

neutron_dynamic_routing/services/bgp/bgp_plugin.py

@@ -14,6 +14,9 @@
 
 from netaddr import IPAddress
 
+from neutron_lib.callbacks import events
+from neutron_lib.callbacks import registry
+from neutron_lib.callbacks import resources
 from neutron_lib import constants as n_const
 from neutron_lib import context
 from neutron_lib.services import base as service_base
@@ -21,9 +24,6 @@ from oslo_config import cfg
 from oslo_log import log as logging
 from oslo_utils import importutils
 
-from neutron.callbacks import events
-from neutron.callbacks import registry
-from neutron.callbacks import resources
 from neutron.common import rpc as n_rpc
 
 from neutron_dynamic_routing.api.rpc.agentnotifiers import bgp_dr_rpc_agent_api  # noqa

neutron_dynamic_routing/services/bgp/scheduler/bgp_dragent_scheduler.py

@@ -13,14 +13,14 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
+from neutron_lib.callbacks import events
+from neutron_lib.callbacks import registry
 from neutron_lib import context as nl_context
 from oslo_db import exception as db_exc
 from oslo_log import log as logging
 from sqlalchemy.orm import exc
 from sqlalchemy import sql
 
-from neutron.callbacks import events
-from neutron.callbacks import registry
 from neutron.db import agents_db
 from neutron.db.models import agent as agent_model
 from neutron.scheduler import base_resource_filter

neutron_dynamic_routing/tests/unit/services/bgp/scheduler/test_bgp_dragent_scheduler.py

@@ -16,11 +16,11 @@
 import mock
 import testscenarios
 
+from neutron_lib.callbacks import events
+from neutron_lib.callbacks import registry
 from neutron_lib import context
 from oslo_utils import importutils
 
-from neutron.callbacks import events
-from neutron.callbacks import registry
 from neutron.tests.unit import testlib_api
 
 from neutron_dynamic_routing.api.rpc.callbacks import resources as dr_resources

neutron_dynamic_routing/tests/unit/services/bgp/test_bgp_plugin.py

@@ -16,10 +16,10 @@
 
 import mock
 
-from neutron.callbacks import events
-from neutron.callbacks import registry
-from neutron.callbacks import resources
 from neutron.tests import base
+from neutron_lib.callbacks import events
+from neutron_lib.callbacks import registry
+from neutron_lib.callbacks import resources
 
 from neutron_dynamic_routing.api.rpc.callbacks import resources as dr_resources
 from neutron_dynamic_routing.db import bgp_db