Project deletion fails for projects with jobs

[uint0]

Description

Projects with jobs cannot be deleted. A 500 error is returned as a result of a foreign key constraint violation job_project_id_fkey.

Expected Behavior

Project is deleted or marked inactive. Is it safe to just immediately cascade delete everything out of the database? Could there be issues with inflight / enqueued tasks?

Steps to reproduce

1. Run the application

2. Create a project

   $ curl -X POST -H 'Content-Type: application/json' -d @sample/project.json localhost:8080/api/projects -i
   HTTP/1.1 201 Created
   content-type: application/json
   content-length: 150
   date: Sat, 19 Mar 2022 10:00:58 GMT
   
   {"uuid":"4fb168e4-b963-431d-85b6-ac108542c036","name":"test_project","description":"This is a sample project to demonstrate Waterwheel","config":null}

3. Create a job in the project

   $ curl -X POST -H 'Content-Type: application/json' -d @sample/jobs/simple.json localhost:8080/api/jobs -i
   HTTP/1.1 201 Created
   content-length: 0
   date: Sat, 19 Mar 2022 10:02:37 GMT
   
   $ curl -i localhost:8080/api/projects/4fb168e4-b963-431d-85b6-ac108542c036/jobs
   HTTP/1.1 200 OK
   content-type: application/json
   content-length: 209
   date: Sat, 19 Mar 2022 10:03:50 GMT
   
   [{"job_id":"51c35e5d-e777-4797-b91b-2526bd4bafdc","name":"simple_job","description":"a simple job to test that waterwheel is working","paused":false,"success":78,"running":0,"failure":0,"waiting":0,"error":0}]

4. Delete the associated project

   $ curl -i -X DELETE localhost:8080/api/projects/4fb168e4-b963-431d-85b6-ac108542c036
   HTTP/1.1 500 Internal Server Error
   content-length: 0
   date: Sat, 19 Mar 2022 10:04:38 GMT

Logs

[2022-03-19T21:04:38.873+11:00 WARN waterwheel::server::api::project]
error deleting project: update or delete on table "project" violates foreign key constraint "job_project_id_fkey" on table "job"
[2022-03-19T21:04:38.873+11:00 ERROR highnoon::filter::log]
response
    method: DELETE
    uri: /api/projects/4fb168e4-b963-431d-85b6-ac108542c036
    status: 500 Internal Server Error

[sphenlee]

Currently all deletions fail because of constraint violations. I don't think we want to cascade delete here, it seems valuable to mark deleted objects as inactive but retain them in the database for history.