add dashboard again

Update users_controller, change strong params
Update user model add accepts_nested_attributes_for location, delete null location
Fix error message
Add dashboard show erb
Add location partial
Change routes



yes, I will go fix this.

I have a question about partial
I want to use
<%= user.location.city %> in user index partial. but 

<%= render partial: "user", collection: @users, as: :user, locals: { location: user.location } %> is not right?