Allow creation of entity models with empty top-level objects.

[davemoore-]

Currently, requesting to create entity models with empty top-level objects (example below) will result in a validation error:

{
  "attributes": {},
  "resolvers": {},
  "matchers": {},
  "indices": {}
}

zentity should allow models like these to be created, and instead validate that they are complete before running a resolution job. This will make it possible to build an application that guides users through the process of creating an entity model from scratch and lets them save their progress on incomplete models.

[davemoore-]

Opened PR #74

[davemoore-]

PR #74 merged into main