Switch to using the skip_because decorator from tempest-lib

Included in tempest-lib 0.2.0 was the migrated skip_because decorator.
This commit switches all the usage of the skip decorator from tempest's
internal copy to use the version in the library where it will be
maintained moving forward.

Change-Id: Ic2d7b9c9247f78aa43cd780e893ce1834a20045e
diff --git a/tempest/api/compute/servers/test_list_server_filters.py b/tempest/api/compute/servers/test_list_server_filters.py
index 7964cf7..375f441 100644
--- a/tempest/api/compute/servers/test_list_server_filters.py
+++ b/tempest/api/compute/servers/test_list_server_filters.py
@@ -13,6 +13,8 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from tempest_lib import decorators
+
 from tempest.api.compute import base
 from tempest.api import utils
 from tempest.common.utils import data_utils
@@ -269,8 +271,8 @@
         self.assertNotIn(self.s2_name, map(lambda x: x['name'], servers))
         self.assertNotIn(self.s3_name, map(lambda x: x['name'], servers))
 
-    @test.skip_because(bug="1182883",
-                       condition=CONF.service_available.neutron)
+    @decorators.skip_because(bug="1182883",
+                             condition=CONF.service_available.neutron)
     @test.attr(type='gate')
     def test_list_servers_filtered_by_ip_regex(self):
         # Filter servers by regex ip
diff --git a/tempest/api/compute/servers/test_server_actions.py b/tempest/api/compute/servers/test_server_actions.py
index 17e3669..9edaede 100644
--- a/tempest/api/compute/servers/test_server_actions.py
+++ b/tempest/api/compute/servers/test_server_actions.py
@@ -17,6 +17,7 @@
 import logging
 import urlparse
 
+from tempest_lib import decorators
 import testtools
 
 from tempest.api.compute import base
@@ -100,7 +101,7 @@
         # The server should be power cycled
         self._test_reboot_server('HARD')
 
-    @test.skip_because(bug="1014647")
+    @decorators.skip_because(bug="1014647")
     @test.attr(type='smoke')
     def test_reboot_server_soft(self):
         # The server should be signaled to reboot gracefully
diff --git a/tempest/api/compute/servers/test_server_group.py b/tempest/api/compute/servers/test_server_group.py
index 0af19c0..fe5dca0 100644
--- a/tempest/api/compute/servers/test_server_group.py
+++ b/tempest/api/compute/servers/test_server_group.py
@@ -13,6 +13,8 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+from tempest_lib import decorators
+
 from tempest.api.compute import base
 from tempest.common.utils import data_utils
 from tempest import test
@@ -74,7 +76,7 @@
         policy = ['anti-affinity']
         self._create_delete_server_group(policy)
 
-    @test.skip_because(bug="1324348")
+    @decorators.skip_because(bug="1324348")
     @test.attr(type='gate')
     def test_create_delete_server_group_with_multiple_policies(self):
         # Create and Delete the server-group with multiple policies
diff --git a/tempest/api/compute/servers/test_virtual_interfaces.py b/tempest/api/compute/servers/test_virtual_interfaces.py
index 48af084..e07a7ed 100644
--- a/tempest/api/compute/servers/test_virtual_interfaces.py
+++ b/tempest/api/compute/servers/test_virtual_interfaces.py
@@ -14,6 +14,7 @@
 #    under the License.
 
 import netaddr
+from tempest_lib import decorators
 
 from tempest.api.compute import base
 from tempest import config
@@ -33,8 +34,8 @@
         resp, server = cls.create_test_server(wait_until='ACTIVE')
         cls.server_id = server['id']
 
-    @test.skip_because(bug="1183436",
-                       condition=CONF.service_available.neutron)
+    @decorators.skip_because(bug="1183436",
+                             condition=CONF.service_available.neutron)
     @test.attr(type='gate')
     @test.services('network')
     def test_list_virtual_interfaces(self):