Fix Fraction validation its undefined message

Add an error message to the validation, whenever no option has been
chosen.
Fix the fraction type validation, test every possible combination of
input.
Merge pull request #35 from mlopez-firstfactory/fallback-mode

Fix Fraction validation its undefined message
Change way to send user answer response for numeric entries and multiple choice.
Update rest angular service
Merge branch 'fallback-mode' of https://github.com/joanrm20/maua into fallback-mode
Merge pull request #105 from joanrm20/fallback-mode

Maua client new user answer response.