Initial version of Flannel using CNI (#1486)

* Updates Controller Manager/Kubelet with Flannel's required configuration for CNI
* Removes old Flannel installation
* Install CNI enabled Flannel DaemonSet/ConfigMap/CNI bins and config (with portmap plugin) on host
* Uses RBAC if enabled
* Fixed an issue that could occur if br_netfilter is not a module and net.bridge.bridge-nf-call-iptables sysctl was not set

roles/network_plugin/flannel/templates/cni-flannel-rbac.yml.j2

@@ -0,0 +1,44 @@
+---
+apiVersion: v1
+kind: ServiceAccount
+metadata:
+  name: flannel
+  namespace: "{{system_namespace}}"
+---
+kind: ClusterRole
+apiVersion: rbac.authorization.k8s.io/v1beta1
+metadata:
+  name: flannel
+rules:
+  - apiGroups:
+      - ""
+    resources:
+      - pods
+    verbs:
+      - get
+  - apiGroups:
+      - ""
+    resources:
+      - nodes
+    verbs:
+      - list
+      - watch
+  - apiGroups:
+      - ""
+    resources:
+      - nodes/status
+    verbs:
+      - patch
+---
+kind: ClusterRoleBinding
+apiVersion: rbac.authorization.k8s.io/v1beta1
+metadata:
+  name: flannel
+roleRef:
+  apiGroup: rbac.authorization.k8s.io
+  kind: ClusterRole
+  name: flannel
+subjects:
+- kind: ServiceAccount
+  name: flannel
+  namespace: "{{system_namespace}}"