create challenge submission & review module

[bnguyenngoc]

use case:
prerequisite:

• a user is in a team

post condition:

• the team is awarded points

Main Scenario

1. a user goes in the challenges page
2. clicks submit on a challenge he wants to be reviewed
3. uploads image/video/text on challenge submission page
4. submits; the challenge in the challenges page is now marked with "in review"
5. admin goes on judge page
6. clicks on challenge to review
7. opens file
8. approves and marks as accepted; challenge is marked with "done"
9. team is awarded points

Alternative Scenarios
8a) does not approve

1. marks as incomplete and sends back
2. team is not awarded points
3. in teams' challenge page, the challenge is marked by "needs work"

8b) admin awards overkill points

1. admin loves submission and awards more points than the max
2. challenge is marked with "overkill"

9a) team wants overkill points

1. same as main scenario, but button "submit" is replaced with "overkill"