Engine: API: fix issue with resource_list for api_version in resource

The API resources were recently updated to optionally include
the :api_version.  This broke the logic that returned
the list of resources in the resource_list api.  As a result,
subscription-manager commands (e.g. register, environments,
orgs) will not work.

This commit will ignore the :api_version in the RAILS
resources  when determing the list to return
as well as omit it from the results sent to the
client.

For example, without this change, the API returns:
{'entitlements': '/api/entitlements/', 'status': '/api/status/', 'packages': '/api/packages/', 'consumers': '/api/consumers/'}

With this change, it will return:
{'status': '/api/status/', 'organizations': '/api/organizations/', 'roles': '/api/roles/', 'tasks': '/api/tasks/', 'sync_plans': '/api/sync_plans/', 'users': '/api/users/', 'distributors': '/api/distributors/', 'providers': '/api/providers/', 'entitlements': '/api/entitlements/', 'gpg_keys': '/api/gpg_keys/', 'repositories': '/api/repositories/', 'environments': '/api/environments/', 'content_views': '/api/content_views/', 'system_groups': '/api/system_groups/', 'products': '/api/products/', 'systems': '/api/systems/', 'changesets': '/api/changesets/', 'activation_keys': '/api/activation_keys/', 'content_view_definitions': '/api/content_view_definitions/', 'packages': '/api/packages/', 'consumers': '/api/consumers/'}