VOL-572: Integration testing with Kubernetes

Updated test_dispatcher to run in the single-node Kubernetes environment, as well as
in docker-compose.

Test_dispatcher.py requires the 'scenario' object literal defined in test_voltha_xpon.py,
which it imports from that file. The import operation appears to cause code in test_voltha_xpon.py
to execute, code which requires containers to be already running. This defeats the automation
that was already built into test_dispatcher by forcing the user to manually deploy containers.
This update removes 'scenario' from test_voltha_xpon.py and puts it in a separate file, which
is then imported by each of these tests.

Change-Id: Ia049ae44686358606939daceab6543e9d455c261
diff --git a/requirements.txt b/requirements.txt
index 6c57a0c..d455022 100755
--- a/requirements.txt
+++ b/requirements.txt
@@ -16,6 +16,7 @@
 jsonpatch==1.16
 kafka_python==1.3.5
 klein==17.10.0
+kubernetes==5.0.0
 netaddr==0.7.19
 networkx==2.0
 nose==1.3.7