Automatically create data subdirectories upon first start of app

[uniqueg]

Describe the bug

When deploying the service, a data directory has to be mounted at /data inside several Docker containers (host directory to be mounted is defined in docker-compose.yaml. The application then needs access to three subdirectories inside that folder:

• db
• output
• tmp

While the first one is automatically created upon the first start of the application, the latter two are not, leading to errors when the user wants to post a workflow run.

To Reproduce

Follow the instructions in README.md to deploy the application and send a POST request to the /runs endpoint.

Expected behavior

Non-existing required directories should be automatically generated when the application is started.