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/requirements.txt b/tcp_tests/requirements.txt
index ca2d0a1..8233a9b 100644
--- a/tcp_tests/requirements.txt
+++ b/tcp_tests/requirements.txt
@@ -15,10 +15,10 @@
 jira
 testrail<=0.3.8
 functools32
-python-k8sclient==0.4.0
+kubernetes
 salt-pepper<=0.5.3
 setuptools<=36.2.0
 netaddr
 mock>=1.2
 python-jenkins
-cmd2<0.9
\ No newline at end of file
+cmd2<0.9