Add phone number field to user model
Add phone number field on user admin
Fix indentation and line length
Add entreprise relation on location model
Add campaigns app

Campaigns app manages all the treid campaings workflow. Campaign
creation associated to an enterprise and with a list of weeks for
locations where the campaign is to be held. It also manages the
promoters assignment to an specific shift for a given campaign.
Add models to campaings app
Add admin view for campaign app
Add view for dayshift on campaigns admin page
Remove extra data from user form on admin page
Add help text on fields