Refactoring of k8s manager and tests

Changes:
 - Official kubernetes python lib
 - Rewrite k8s api wrapper in OOP manner
 - Use api where its possible instead of cli
 - Remove virtlet code because its can be replaced with pod api
 - Remove unused/oudated manager code
 - Remove bug workaround in k8s upgrade template
 - Remove netchecker obsolete code
 - Remove unfinished test_rbd_flexvolume_driver

Change-Id: I446a240123282196a6ba54f588aea84791f175ba
Related-PROD: PROD-21700
diff --git a/tcp_tests/managers/k8s/persistentvolumes.py b/tcp_tests/managers/k8s/persistentvolumes.py
index 8ab7ec2..7424935 100644
--- a/tcp_tests/managers/k8s/persistentvolumes.py
+++ b/tcp_tests/managers/k8s/persistentvolumes.py
@@ -12,46 +12,43 @@
 #    License for the specific language governing permissions and limitations
 
 
+from kubernetes import client
+
 from tcp_tests.managers.k8s.base import K8sBaseResource
 from tcp_tests.managers.k8s.base import K8sBaseManager
 
 
 class K8sPersistentVolume(K8sBaseResource):
-    """docstring for K8sPersistentVolume"""
+    resource_type = 'persistentvolume'
 
-    def __repr__(self):
-        return "<K8sPersistentVolume: %s>" % self.name
+    def _read(self, **kwargs):
+        return self._manager.api.read_persistent_volume(self.name, **kwargs)
 
-    @property
-    def name(self):
-        return self.metadata.name
+    def _create(self, body, **kwargs):
+        return self._manager.api.create_persistent_volume(body, **kwargs)
+
+    def _patch(self, body, **kwargs):
+        return self._manager.api.patch_persistent_volume(
+            self.name, body, **kwargs)
+
+    def _replace(self, body, **kwargs):
+        return self._manager.api.replace_persistent_volume(
+            self.name, body, **kwargs)
+
+    def _delete(self, **kwargs):
+        self._manager.api.delete_persistent_volume(
+            self.name, client.V1DeleteOptions(), **kwargs)
 
 
 class K8sPersistentVolumeManager(K8sBaseManager):
-    """docstring for ClassName"""
-
     resource_class = K8sPersistentVolume
 
-    def _get(self, name, **kwargs):
-        return self.api.read_namespaced_persistent_volume(
-            name=name, **kwargs)
+    @property
+    def api(self):
+        return self._cluster.api_core
 
-    def _list(self, **kwargs):
-        return self.api.list_namespaced_persistent_volume(
-            **kwargs)
+    def _list(self, namespace, **kwargs):
+        return self.api.list_persistent_volume(**kwargs)
 
-    def _create(self, body, **kwargs):
-        return self.api.create_namespaced_persistent_volume(
-            body, **kwargs)
-
-    def _replace(self, body, name, **kwargs):
-        return self.api.replace_namespaced_persistent_volume(
-            body=body, name=name, **kwargs)
-
-    def _delete(self, body, name, **kwargs):
-        return self.api.delete_namespaced_persistent_volume(
-            body=body, name=name, **kwargs)
-
-    def _deletecollection(self, **kwargs):
-        return self.api.deletecollection_namespaced_persistent_volume(
-            **kwargs)
+    def _list_all(self, **kwargs):
+        return self._list(None, **kwargs)