Remove circle reference

We can not import magnum.api.validation because of circle reference.

We can reproduce this bug by "tox -egenconfig" or importing
magnum.api.validation in a python console.

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "magnum/api/validation.py", line 20, in <module>
    from magnum.api.controllers.v1 import utils as api_utils
  File "magnum/api/controllers/v1/__init__.py", line 30, in <module>
    from magnum.api.controllers.v1 import baymodel
  File "magnum/api/controllers/v1/baymodel.py", line 29, in <module>
    from magnum.api import validation
ImportError: cannot import name validation

Change-Id: Ib73d7f1d989b9bc860bfadafa52e9a83996f5de9
Closes-Bug: #1521840

magnum/api/controllers/v1/bay.py

@@ -24,8 +24,8 @@ from magnum.api.controllers import base
 from magnum.api.controllers import link
 from magnum.api.controllers.v1 import collection
 from magnum.api.controllers.v1 import types
-from magnum.api.controllers.v1 import utils as api_utils
 from magnum.api import expose
+from magnum.api import utils as api_utils
 from magnum.common import exception
 from magnum.common import policy
 from magnum import objects

magnum/api/controllers/v1/baymodel.py

@@ -24,8 +24,8 @@ from magnum.api.controllers import base
 from magnum.api.controllers import link
 from magnum.api.controllers.v1 import collection
 from magnum.api.controllers.v1 import types
-from magnum.api.controllers.v1 import utils as api_utils
 from magnum.api import expose
+from magnum.api import utils as api_utils
 from magnum.api import validation
 from magnum.common import clients
 from magnum.common import exception

magnum/api/controllers/v1/certificate.py

@@ -22,7 +22,7 @@ import wsmeext.pecan as wsme_pecan
 from magnum.api.controllers import base
 from magnum.api.controllers import link
 from magnum.api.controllers.v1 import types
-from magnum.api.controllers.v1 import utils as api_utils
+from magnum.api import utils as api_utils
 from magnum.common import exception
 from magnum.common import policy
 from magnum import objects

magnum/api/controllers/v1/container.py

@@ -24,8 +24,8 @@ from magnum.api.controllers import base
 from magnum.api.controllers import link
 from magnum.api.controllers.v1 import collection
 from magnum.api.controllers.v1 import types
-from magnum.api.controllers.v1 import utils as api_utils
 from magnum.api import expose
+from magnum.api import utils as api_utils
 from magnum.api import validation
 from magnum.common import exception
 from magnum.common import policy

magnum/api/controllers/v1/node.py

@@ -23,8 +23,8 @@ from magnum.api.controllers import base
 from magnum.api.controllers import link
 from magnum.api.controllers.v1 import collection
 from magnum.api.controllers.v1 import types
-from magnum.api.controllers.v1 import utils as api_utils
 from magnum.api import expose
+from magnum.api import utils as api_utils
 from magnum.common import exception
 from magnum.common import policy
 from magnum import objects

magnum/api/controllers/v1/pod.py

@@ -21,8 +21,8 @@ from magnum.api.controllers import link
 from magnum.api.controllers.v1 import base as v1_base
 from magnum.api.controllers.v1 import collection
 from magnum.api.controllers.v1 import types
-from magnum.api.controllers.v1 import utils as api_utils
 from magnum.api import expose
+from magnum.api import utils as api_utils
 from magnum.api import validation
 from magnum.common import exception
 from magnum.common import k8s_manifest

magnum/api/controllers/v1/replicationcontroller.py

@@ -22,8 +22,8 @@ from magnum.api.controllers import link
 from magnum.api.controllers.v1 import base as v1_base
 from magnum.api.controllers.v1 import collection
 from magnum.api.controllers.v1 import types
-from magnum.api.controllers.v1 import utils as api_utils
 from magnum.api import expose
+from magnum.api import utils as api_utils
 from magnum.api import validation
 from magnum.common import exception
 from magnum.common import k8s_manifest

magnum/api/controllers/v1/service.py

@@ -20,8 +20,8 @@ from magnum.api.controllers import link
 from magnum.api.controllers.v1 import base as v1_base
 from magnum.api.controllers.v1 import collection
 from magnum.api.controllers.v1 import types
-from magnum.api.controllers.v1 import utils as api_utils
 from magnum.api import expose
+from magnum.api import utils as api_utils
 from magnum.api import validation
 from magnum.common import exception
 from magnum.common import k8s_manifest

magnum/api/controllers/v1/x509keypair.py

@@ -23,7 +23,7 @@ from magnum.api.controllers import base
 from magnum.api.controllers import link
 from magnum.api.controllers.v1 import collection
 from magnum.api.controllers.v1 import types
-from magnum.api.controllers.v1 import utils as api_utils
+from magnum.api import utils as api_utils
 from magnum.common import exception
 from magnum import objects
 

magnum/api/validation.py

@@ -17,7 +17,7 @@ import decorator
 from oslo_config import cfg
 import pecan
 
-from magnum.api.controllers.v1 import utils as api_utils
+from magnum.api import utils as api_utils
 from magnum.common import exception
 from magnum import objects
 

magnum/tests/unit/api/controllers/v1/test_certificate.py

@@ -23,7 +23,7 @@ from magnum.tests.unit.objects import utils as obj_utils
 
 class TestCertObject(base.TestCase):
 
-    @mock.patch('magnum.api.controllers.v1.utils.get_rpc_resource')
+    @mock.patch('magnum.api.utils.get_rpc_resource')
     def test_cert_init(self, mock_get_rpc_resource):
         cert_dict = apiutils.cert_post_data()
         mock_bay = mock.MagicMock()

magnum/tests/unit/api/controllers/v1/test_utils.py

@@ -17,7 +17,7 @@ import jsonpatch
 import mock
 import wsme
 
-from magnum.api.controllers.v1 import utils
+from magnum.api import utils
 from magnum.common import exception
 from magnum.common import utils as common_utils
 from magnum.tests.unit.api import base

magnum/tests/unit/api/test_validation.py

@@ -188,7 +188,7 @@ class TestValidation(base.BaseTestCase):
             assert_raised=True)
 
     @mock.patch('pecan.request')
-    @mock.patch('magnum.api.controllers.v1.utils.get_rpc_resource')
+    @mock.patch('magnum.api.utils.get_rpc_resource')
     def _test_enforce_network_driver_types_update(
             self,
             mock_get_rpc_resource,