consume WarningsFixture from neutron-lib

The WarningsFixture is in neutron-lib. This patch consumes it by
removing it from neutron and using from lib instead.

NeutronLibImpact

Change-Id: I4a04ca25e56b1d93ae49026b35d108a89545447a

neutron/tests/base.py

@@ -55,7 +55,6 @@ from neutron import manager
 from neutron import policy
 from neutron.quota import resource_registry
 from neutron.tests import post_mortem_debug
-from neutron.tests import tools
 
 
 CONF = cfg.CONF
@@ -230,7 +229,7 @@ class DietTestCase(base.BaseTestCase):
                 debugger))
 
         # Make sure we see all relevant deprecation warnings when running tests
-        self.useFixture(tools.WarningsFixture())
+            self.useFixture(fixture.WarningsFixture(module_re=['^neutron\\.']))
 
         self.useFixture(fixture.DBQueryHooksFixture())
 

neutron/tests/tools.py

@@ -15,7 +15,6 @@
 
 import datetime
 import random
-import warnings
 
 import fixtures
 import netaddr
@@ -39,20 +38,6 @@ except ImportError as e:
     _CALLBACK_PRIORITY_SUPPORTED = False
 
 
-class WarningsFixture(fixtures.Fixture):
-    """Filters out warnings during test runs."""
-
-    warning_types = (
-        DeprecationWarning, PendingDeprecationWarning, ImportWarning
-    )
-
-    def _setUp(self):
-        self.addCleanup(warnings.resetwarnings)
-        for wtype in self.warning_types:
-            warnings.filterwarnings(
-                "once", category=wtype, module='^neutron\\.')
-
-
 class SafeCleanupFixture(fixtures.Fixture):
     """Catch errors in daughter fixture cleanup."""