Adding a custom action to Devise Registrations..Unknown Action Error - ruby-on-rails

Question

After Googling everywhere about how I can fix this I decided to post a question. I'm trying to add a custom action "create_pro" to the Devise Registrations controller so I can create a user with additional fields (A pro user). This form is on the same page as the devise create action for a user.
I keep getting the following error after submitting the form:
Unknown action
The action 'create_pro' could not be found for
Devise::RegistrationsController
How can I fix this?
Routes
devise_for :users,:controllers => { :registrations => "registrations" }
devise_scope :user do
post "gopro", :to => "devise/registrations#create_pro"
end
Registrations Controller
class RegistrationsController < Devise::RegistrationsController
before_filter :authenticate_user!, :only => :token
def new
super
end
def create
#user = User.new(params[:user])
if #user.save
sign_in #user
flash[:notice] = "Welcome to Banking Analytics."
redirect_to '/mybank'
else
render :action => :new
end
end
def create_pro
#user = User.new(params[:user])
if #user.save
sign_in #user
flash[:notice] = "Welcome to Banking Analytics."
redirect_to '/mybank'
else
render :action => :new
end
end
end
View
<div class="signup_form_basic">
<%= simple_form_for #user, :url => url_for(:controller => 'registrations', :action => 'create_pro') do |f| %>
<%= f.error_notification %>
<%= f.input :email, :required => true, :autofocus => true, :label => 'Username ( Your Email )', :placeholder => 'Email Address' %>
<%= f.input :password, :required => true, :autofocus => true, :label => 'Password', :placeholder => 'Password' %>
<%= f.input :password_confirmation, :required => true, :autofocus => true, :label => 'Confirm Password', :placeholder => 'Password Confirmation' %>
<%= f.button :submit, "Sign Up >>", class: 'btn btn-inverse' %>
<% end %>
</div>

Answer 1

I don't have an answer for the 'Unknown Action error' that you are facing, but I think the current solution is sub-optimal.
Since your goal is to have the following two classes of users
Pro-users, and
Regular (Non-pro) users,
it is probably best to follow the suggestion at How To: Customize routes to user registration pages and set up parallel structures for the two types of users.
That would be much more in line with the relationship between the two types of users.