Cloned from https://bugzilla.redhat.com/show_bug.cgi?id=1230873
Description of problem:
An organization can be associated with zero or more realms. Unfortunately, the API does not provide information about this organization → realm relationship.

Version-Release number of selected component (if applicable):
Tested against Satellite 6.1.0 GA 8. Foreman-debug is attached.

How reproducible:
100%

Steps to Reproduce:
1. Create an organization and associate it with a realm.
2. Get information about the organization with an HTTP GET request to /katello/api/v2/organizations/:id
3. Inspect the returned JSON payload. No mention of associated realms is made.

Actual results:

>>> from nailgun import entities
    >>> org = entities.Organization().create(create_missing=True)
    >>> org_attrs = org.read_json()
    >>> org_attrs.keys()
    [
        u'compute_resources',
        u'config_templates',
        u'created_at',
        u'default_content_view_id',
        u'default_info',
        u'description',
        u'domains',
        u'environments',
        u'hostgroups',
        u'id',
        u'label',
        u'library_id',
        u'locations',
        u'media',
        u'name',
        u'owner_details',
        u'parameters',
        u'redhat_docker_registry_url',
        u'redhat_repository_url',
        u'select_all_types',
        u'service_level',
        u'service_levels',
        u'smart_proxies',
        u'subnets',
        u'title',
        u'updated_at',
        u'users',
    ]

Expected results:
Information about realms is included.

Additional info:
n/a