warning when passing string literal "None" as spec.tls.caSecretName

[ObiWahn]

This line in tests/scale_test.go produces the following warning:

2018-03-21T14:19:42Z |WARN| Failed to handle event
component=operator
error="invalid deployment spec. please fix the following problem with the deployment 
    spec:
        spec.tls: Name 'None' is not a valid resource name:
        spec.tls: Name 'None' is not a valid resource name"

[ObiWahn]

It works with a lowercase "none". So we should either update the documentation or change the internals. I am a bit surprised that it is not working with uppercase "None". When we do not match then no-tls case, then the given string should be used as secret. Furthermore it prevents the cluster from starting. This is enough reason to fail with a fatal error.
The last remaining secret to me is how the test that is already for some time on master could work for @kvahed .

[ObiWahn]

"None" does not pass here:

kube-arangodb/pkg/util/k8sutil/names.go

Line 53 in cd44faa

if resourceNameRE.MatchString(name) {