Adding a field to capture the efforts spent by user for Task

[aah-74]

The submission page for Challenge submission is getting modified. In place of the zip file upload, we are expecting a filed where URL of the code will be added by submitter.

For Harvard experiments ( and also as feature) we want to have one more field to capture the efforts spent ( in person hours) by the submitter. While submitting for the challenge, the submitter should enter the efforts spent data in that field.
@ajefts please check. thanks