VOL-572: Integration testing with Kubernetes

* Updated the Kubernetes version installed in the single-node environment from 1.8.5 to 1.9.3.
* Replaced the Weave pod network plugin with Calico
* Updated test_device_state_changes to run in single-node Kubernetes
* Moved test_utils.py from voltha/tests/itests/docutests/ to voltha/tests/itests/.

Change-Id: I472cffec1e0c3a783edaecb375664cd1c6bb93b1
diff --git a/tests/itests/docutests/build_md_test.py b/tests/itests/docutests/build_md_test.py
index 6a00f71..6f6c018 100644
--- a/tests/itests/docutests/build_md_test.py
+++ b/tests/itests/docutests/build_md_test.py
@@ -29,7 +29,7 @@
 
 this_dir = os.path.abspath(os.path.dirname(__file__))
 
-from test_utils import run_command_to_completion_with_raw_stdout, \
+from tests.itests.test_utils import run_command_to_completion_with_raw_stdout, \
     is_open, \
     is_valid_ip, \
     run_long_running_command_with_timeout, \