Starter Kit: Backend updates for Open Sentencing

### Background on the problem the feature will solve/improved user experience
Update the backend to support the front end.

### Describe the solution you'd like
The backend has been deployed to [IBM Code Engine](https://open-sentencing-aggregator-app.deoblc6jtd1.us-south.codeengine.appdomain.cloud/openapi/ui/).
- [ ] connect backend to a couchdb database
- [ ] implement end points as described in the [swagger docs](https://open-sentencing-aggregator-app.deoblc6jtd1.us-south.codeengine.appdomain.cloud/openapi/ui/)
- [ ] populate backend with mock data. You can use a framework like [faker](https://github.com/joke2k/faker).
- [ ] Complete related issues listed below

### Related Issues
- [ ] #21
- [ ] #22
- [ ] #25
- [ ] #30
- [ ] #32

### Acceptance Criteria
The backend is connected to a central database and returns sensible mock data. Front end can use the API hosted on code engine.