Adding a test for serializing multiple resources in a JSON-API document.
Adding test for serializing a paginated JSON-API document.
Adding a test for serializing an empty paginated JSON-API document.
Returning pagination data even with an empty response.
Merge pull request #6 from GoIntegro/hotfix/api-55-empty-page

[API-55] Pagination is now returning metadata always.
Merge remote-tracking branch 'origin/master' into feature/api-48-create-resources

Conflicts:
	JsonApi/Document.php