Add profiles to users

@cgruppioni @georgetmayorga
Doing it the normal way as expected in the form_for on a singular resource hits an error, as discussed on: https://github.com/rails/rails/issues/1769. It seems like a very common problem when using singular resources and form_for for creates/updates.

I tried to put these routes within resource :profile under users, but that ran into many issues, even if I changed the form for route to:

```
<h2>Create Profile</h2>
<div class="new_profile_form">
  <%= form_for [@user, @profile] do |form| %>
    <%= render "form", form: form %>
  <% end %>
</div>
```

Hits an error for an undefined method user_profile_path. There's a workaround in that thread at https://github.com/rails/rails/issues/1769#issuecomment-9556381, which works.