Expose Database models in web API

[nphilipp]

Story

As a user of Duffy,
I want to be able to manage the various objects via the API,
because doing this with a DB CLI tool plain sucks.

Acceptance Criteria

API endpoints exist to add/edit/delete…

• Projects: Expose project endpoint #86
• Users: Expose user endpoint #80
• SSH Keys: Expose SSH key endpoint #91
• Nodes: Expose node endpoint #89
• Sessions: Expose session endpoint #87

Background

Individual endpoints should provide a “RESTful” API, i.e. fulfil these acceptance criteria:

# Acceptance Criteria

Implement…
- [ ] a `GET` method to list items of the type
- [ ] a `POST` method to create new items of the type
- [ ] a `DELETE` method to delete items of a type (only where applicable?)

[nphilipp]

Closing this as all tracked issues are done.