Add avatar binding to index html.
Hide challenge section when 'challenge object' does not exists
Add method to load challenge objects.
Remove '%s about how many users selected each answer' from non 'single response multiple choice'.
Add images versions constants.
Change 'History' text by 'Your progress' (dashboard).
Change 'get your score prediction' button color.
Merge pull request #58 from joanrm20/master

Maua client new features
Integrate challenge games.
Merge pull request #59 from joanrm20/master

Maua client new features
Add Fix to hide explanation section when there is no explanation for the multiple choice answers.
Move challenge function from controller to directive.
Add iteration over challenges games.
Add new create game request.
Merge pull request #60 from joanrm20/master

Maua client new features
Rename error functions.
remove old practice logic directory.
Remove 'GRE' restriction for 'group practice'
Merge pull request #61 from joanrm20/master

Maua client fix
Merge from upstream