`snactor discover --safe` doesn't detect topics and workflows

[vojtechsokol]

Reproducer: Create new repository with tag and/or topic:

$ snactor repo new NewRepo
New repository NewRepo has been created in /home/user/NewRepo
$ snactor new-topic NewTopic
New topic Topic has been created in /home/user/NewRepo/topics/newtopic.py
$ snactor workflow new NewWorkflow
New tag WorkflowTag has been created in /home/user/NewRepo/tags/newworkflow.py
New workflow Workflow has been created in /home/user/NewRepo/workflows/new_workflow.py

Running snactor discover --safe doesn't detect the created topic and workflow:

$ snactor discover --safe
Repository:
  Name: NewRepo
  Path: /home/user/NewRepo

Actors

Models

Tags
  - NewWorkflowTag(Tag) ........................................ tags/newworkflow.py

Expected behavior:

$ snactor discover --safe
Repository:
  Name: NewRepo
  Path: /home/user/NewRepo

Actors

Models

Tags
  - NewWorkflowTag(Tag) ............................... tags/newworkflow.py

Topics
  - NewTopic(Topic) ................................... topics/newtopic.py

Workflows
  - NewWorkflow(Workflow) ............................. workflows/new_workflow.py