Get clusters command not working

[rcarrata]

In RHACM 2.1 the CR for oc get clusters -A doesn't exist:

# oc get clusters -A --show-labels
error: the server doesn't have a resource type "clusters"

This command can be substituted by managedclusterinfo command available in ACM 2.x

# oc get managedclusterinfo -A --show-labels
NAMESPACE       NAME            AGE     LABELS
dev             dev             4h29m   cloud=Amazon,clusterID=xxxx,env=dev,environment=dev,name=dev,region=eu-west-1,vendor=OpenShift
local-cluster   local-cluster   23h     cloud=Amazon,clusterID=xxxx,installer.name=multiclusterhub,installer.namespace=open-cluster-management,local-cluster=true,name=local-cluster,vendor=OpenShift
prod            prod            44m     cloud=AWS,clusterID=xxxx,env=prod,environment=prod,name=prod,vendor=OpenShift
qa              qa              17m     cloud=GCP,clusterID=xxxx,env=qa,environment=qa,name=qa,vendor=OpenShift

ACM Version release-2.1:

# oc get subs -n open-cluster-management
NAME                        PACKAGE                       SOURCE             CHANNEL
acm-operator-subscription   advanced-cluster-management   redhat-operators   release-2.1

[rcarrata]

PR (#5) to solve this issue generated.