Fast 72hrs! Topcoder Direct - Support Challenges With Zero Prize

For this challenge, we'd like to update the logic when creating challenges in Direct to allow $0 prizes. This is used for fun challenges and a few other use cases. We should also update the validation in Online Review to allow for this.

Currently, if you set $0 prize on a challenge in Direct it looks like it simply does not create the prize records in the DB, which causes errors when editing/closing challenges/tasks.

Generally, you should make the necessary changes and complete the verification that the Topcoder Direct and Online Review system can properly handle this specific case.

How To Verify

1. Create a $0 prize Challenge using Topcoder Direct and activiate it.
2. Register one or more submittters and reviewers through Online Review
3. Submitters have to make submissions during the Submission phase
4. Reviewers have to submit scorecards during the Review phase
5. Let the autopilot to move phases and verify everything is working properly.

Local Setup

- Please use the dev branch of https://github.com/appirio-tech/direct-app for development.
- Please check https://github.com/appirio-tech/tc-common-tutorials/blob/master/docker/direct-app/ for how to setup and run locally.
- Please follow https://github.com/appirio-tech/tc-common-tutorials/tree/master/docker/online_review to build online review and autopilot docker images, and add the related services in docker-compose.yaml 
- There is a limitation about the maxinum usage of connections for informix, so for your testing, you'd better run direct and online review services separately.
- similar like  docker-compose start tc-direct-with-voume/run-online-review/run-autopilot,  docker-compose stop tc-direct-with-voume/run-online-review/run-autopilot 

Final Submission Guidelines

- Code Changes For Direct App
- Code Changes For Online Review
- Verification Steps