Removes authors array from discussion

I believe it doesn't make sense to send an array of users in the
discussion. If you have a User model the data gets cached and can be
used in different places. If the application evolves having another data
structure like Discussion that needs users you would have two places where you'll send a
list of users.
Revert "Removes authors array from discussion"

This reverts commit b9081869c4e3f03bc07402127d732f3fed856b2e.
Allows users to change their password
Fix log in style on desktop