Error when templates are retrieved from cloud storage

Hi,

I'am storing the templates into cloud storage. For exemple to create a bucket, my config looks like this :
resources:
````yaml
- name: my-bucket
type: gs://MY TEMPLATES BUCKET/templates/gcs_bucket/gcs_bucket.py
properties:
name: my-bucket
location: us-east1
````
When running the deployment manager, I'm geeting the following error:

````
ERROR: (gcloud.deployment-manager.deployments.update) Error in Operation [operation-XXX]: errors:
- code: MANIFEST_EXPANSION_USER_ERROR
location: /deployments/resources/manifests/manifest-XXXX
message: |-
Manifest expansion encountered the following errors: Invalid properties for 'gs://gto-deployment-manager-templates/templates/gcs_bucket/gcs_bucket.py':
File 'gcs_bucket.py' requested in schema 'gs://gto-deployment-manager-templates/templates/gcs_bucket/gcs_bucket.py.schema' but not included with imports.
Resource: gto-deployment-manager-templates Resource: config
````

In fact, the schema is referencing ``gcs_bucket.py`` which the deployment likely cannot find (I presume because it's not stored localy):

`````
imports:
- path: gcs_bucket.py
`````

A workaround for this is to simply remove the import.

Is this import mandatory? Can we get rid of it ? (This import is not present in all templates)

Thanks for your help,