@inv_client.create_resource does not return path when resource already exists

[pilhuhn]

This goes

def create_resource_under_resource
...
      rescue HawkularException => error
        # 409 We already exist -> that is ok
        raise unless error.status_code == 409
      end
      Resource.new(res)

In case of the 409, we still return a Resource, but constructed from the input, which does not contain the path.

The path needs to be obtained by clients like this:

resource = @inv_client.create_resource  type_path, data['r'], data['r']
  if resource.path.nil?
    resources = @inv_client.list_resources_for_type type_path, true
    resource = resources.first
  end

We should perhaps internalise getting the path into create_resource to have a consistent behaviour in both cases.