Export fails when no name is present

[michaelsauter]

E.g. tailor export rolebinding -n foo-dev might fail with:

2019/10/07 16:06:03 Could not export Kinds: [RoleBinding], Name: , Label: , ExcludedKinds: [], ExcludedNames: [], ExcludedLabels: [] resources as template: Could not parse object of exported template: Object has no key 'name'

The reason is that

tailor/pkg/openshift/item.go

Lines 124 to 128 in 1fff4cf

	namePointer, _ := gojsonpointer.NewJsonPointer("/metadata/name")
	name, _, err := namePointer.Get(m)
	if err != nil {
	return err
	}

expects /metadata/name to exist, however some resources might not have it, e.g.:

- apiVersion: authorization.openshift.io/v1
  groupNames: null
  kind: RoleBinding
  metadata:
    creationTimestamp: null
    generateName: system:image-pusher-
  roleRef:
    name: system:image-pusher
  subjects:
  - kind: ServiceAccount
    name: default
    namespace: foo-dev
  userNames:
  - system:serviceaccount:foo-dev:default