Error when a package has no models

When we add a package with no models, we get an error ModuleNotFoundError.

created merge request !55 (merged) to address this issue

By Jean-Baptiste on 2019-04-16T08:00:32 (imported from GitLab project)

mentioned in merge request !55 (merged)

By Jean-Baptiste on 2019-04-16T08:00:33 (imported from GitLab project)

closed via merge request !55 (merged)

By Jean-Baptiste on 2019-04-16T08:11:10 (imported from GitLab project)

mentioned in commit a1e3ce8e

By Jean-Baptiste on 2019-04-16T08:11:10 (imported from GitLab project)