CRB: set namespace

currently a static namespace is set at CRB in serviceaccount.yaml. make it dynamic! a sample resource applied to eupt-dev looks like this:

apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: 'eupt-dev-vault'
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: system:auth-delegator
subjects:
  - kind: ServiceAccount
    name: eupt-textapi
    namespace: eupt-dev