Fix for a flaky test failing because k8s is slow

We create a deployment and do the following:

```
self.assertIsNotNone(dep)
```

Which does not fail, and then the code proceeds to deletion
and fails with a 404 execption in 80% of the time, but sometimes
it works. The deployment is there, but for some reason not available for
deletion.
Travis CI also showed inconsitent behaviour on this. Python3.5 passed
but all other version failed.
With this commit we wait for the deployment to become available for
deletion and only then continue.

kubernetes/e2e_test/test_utils.py

@@ -16,6 +16,7 @@
 
 import yaml
 from kubernetes import utils, client
+from kubernetes.client.rest import ApiException
 from kubernetes.e2e_test import base
 
 
@@ -39,9 +40,14 @@ def test_create_apps_deployment_from_yaml(self):
         dep = app_api.read_namespaced_deployment(name="nginx-app",
                                                  namespace="default")
         self.assertIsNotNone(dep)
-        app_api.delete_namespaced_deployment(
-            name="nginx-app", namespace="default",
-            body={})
+        while True:
+            try:
+                app_api.delete_namespaced_deployment(
+                    name="nginx-app", namespace="default",
+                    body={})
+                break
+            except ApiException:
+                continue
 
     def test_create_apps_deployment_from_yaml_string(self):
         k8s_client = client.api_client.ApiClient(configuration=self.config)
@@ -55,9 +61,14 @@ def test_create_apps_deployment_from_yaml_string(self):
         dep = app_api.read_namespaced_deployment(name="nginx-app",
                                                  namespace="default")
         self.assertIsNotNone(dep)
-        app_api.delete_namespaced_deployment(
-            name="nginx-app", namespace="default",
-            body={})
+        while True:
+            try:
+                app_api.delete_namespaced_deployment(
+                    name="nginx-app", namespace="default",
+                    body={})
+                break
+            except ApiException:
+                continue
 
     def test_create_apps_deployment_from_yaml_obj(self):
         k8s_client = client.api_client.ApiClient(configuration=self.config)
@@ -71,9 +82,14 @@ def test_create_apps_deployment_from_yaml_obj(self):
         dep = app_api.read_namespaced_deployment(name="nginx-app",
                                                  namespace="default")
         self.assertIsNotNone(dep)
-        app_api.delete_namespaced_deployment(
-            name="nginx-app", namespace="default",
-            body={})
+        while True:
+            try:
+                app_api.delete_namespaced_deployment(
+                    name="nginx-app", namespace="default",
+                    body={})
+                break
+            except ApiException:
+                continue
 
     def test_create_extensions_deployment_from_yaml(self):
         """