Migrate cvp-sanity to Python3

* use print function from future
* convert dict keys and values to list
* do not use bunch imports
* fix requirements mismatch
Related: PROD-33849

Change-Id: Ifecc3a9dcdcfe3243f7dcf2c709a80e9a7c765a1
(cherry picked from commit e32e3f9ea37a24da5365dcef2a13609057b61923)
diff --git a/test_set/cvp-sanity/tests/test_k8s.py b/test_set/cvp-sanity/tests/test_k8s.py
index aac6edf..0bf1b06 100644
--- a/test_set/cvp-sanity/tests/test_k8s.py
+++ b/test_set/cvp-sanity/tests/test_k8s.py
@@ -179,7 +179,7 @@
         param='curl {} 2>&1 | grep kubernetesDashboard'.format(url),
         expr_form='pillar'
     )
-    assert len(check.values()[0]) != 0, (
+    assert len(list(check.values())[0]) != 0, (
         'Kubernetes dashboard is not reachable on {} from '
         'ctl nodes'.format(url)
     )