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/tests/system/testdata/k8s/cirros-vm.yaml b/tcp_tests/tests/system/testdata/k8s/cirros-vm.yaml
new file mode 100644
index 0000000..5cac75b
--- /dev/null
+++ b/tcp_tests/tests/system/testdata/k8s/cirros-vm.yaml
@@ -0,0 +1,41 @@
+# From virtlet/examples/cirros-vm.yaml
+apiVersion: v1
+kind: Pod
+metadata:
+  name: cirros-vm
+  annotations:
+    # This tells CRI Proxy that this pod belongs to Virtlet runtime
+    kubernetes.io/target-runtime: virtlet.cloud
+    # CirrOS doesn't load nocloud data from SCSI CD-ROM for some reason
+    VirtletDiskDriver: virtio
+    # inject ssh keys via cloud-init
+    VirtletSSHKeys: |
+      ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQCaJEcFDXEK2ZbX0ZLS1EIYFZRbDAcRfuVjpstSc0De8+sV1aiu+dePxdkuDRwqFtCyk6dEZkssjOkBXtri00MECLkir6FcH3kKOJtbJ6vy3uaJc9w1ERo+wyl6SkAh/+JTJkp7QRXj8oylW5E20LsbnA/dIwWzAF51PPwF7A7FtNg9DnwPqMkxFo1Th/buOMKbP5ZA1mmNNtmzbMpMfJATvVyiv3ccsSJKOiyQr6UG+j7sc/7jMVz5Xk34Vd0l8GwcB0334MchHckmqDB142h/NCWTr8oLakDNvkfC1YneAfAO41hDkUbxPtVBG5M/o7P4fxoqiHEX+ZLfRxDtHB53 me@localhost
+spec:
+  # This nodeAffinity specification tells Kubernetes to run this
+  # pod only on the nodes that have extraRuntime=virtlet label.
+  # This label is used by Virtlet DaemonSet to select nodes
+  # that must have Virtlet runtime
+  affinity:
+    nodeAffinity:
+      requiredDuringSchedulingIgnoredDuringExecution:
+        nodeSelectorTerms:
+        - matchExpressions:
+          - key: extraRuntime
+            operator: In
+            values:
+            - virtlet
+  containers:
+  - name: cirros-vm
+    # This specifies the image to use.
+    # virtlet.cloud/ prefix is used by CRI proxy, the remaining part
+    # of the image name is prepended with https:// and used to download the image
+    image: virtlet.cloud/cirros
+    imagePullPolicy: IfNotPresent
+    # tty and stdin required for `kubectl attach -t` to work
+    tty: true
+    stdin: true
+    resources:
+      limits:
+        # This memory limit is applied to the libvirt domain definition
+        memory: 160Mi