Add and apply rubocop rules for empty lines

We were very inconsistent regarding these rules.

Personally I prefer no empty lines around blocks, clases, etc... as
recommended by the Ruby style guide [1], and they're the default values
in rubocop, so those are the settings I'm applying.

The exception is the `private` access modifier, since we were leaving
empty lines around it most of the time. That's the default rubocop rule
as well. Personally I don't have a strong preference about this one.


[1] https://rubystyle.guide/#empty-lines-around-bodies

app/controllers/admin/poll/active_polls_controller.rb

@@ -31,5 +31,4 @@ class Admin::Poll::ActivePollsController < Admin::Poll::BaseController
     def active_poll_params
       params.require(:active_poll).permit(translation_params(ActivePoll))
     end
-
 end

app/controllers/admin/poll/base_controller.rb

@@ -6,5 +6,4 @@ class Admin::Poll::BaseController < Admin::BaseController
     def namespace
       "admin"
     end
-
 end

app/controllers/admin/poll/booth_assignments_controller.rb

@@ -1,5 +1,4 @@
 class Admin::Poll::BoothAssignmentsController < Admin::Poll::BaseController
-
   before_action :load_poll, except: [:create, :destroy]
 
   def index
@@ -74,5 +73,4 @@ class Admin::Poll::BoothAssignmentsController < Admin::Poll::BaseController
     def load_search
       @search = search_params[:search]
     end
-
 end

app/controllers/admin/poll/booths_controller.rb

@@ -41,5 +41,4 @@ class Admin::Poll::BoothsController < Admin::Poll::BaseController
     def booth_params
       params.require(:poll_booth).permit(:name, :location)
     end
-
 end

app/controllers/admin/poll/officer_assignments_controller.rb

@@ -1,5 +1,4 @@
 class Admin::Poll::OfficerAssignmentsController < Admin::Poll::BaseController
-
   before_action :load_poll
   before_action :redirect_if_blank_required_params, only: [:by_officer]
   before_action :load_booth_assignment, only: [:create]
@@ -66,5 +65,4 @@ class Admin::Poll::OfficerAssignmentsController < Admin::Poll::BaseController
     def load_search
       @search = search_params[:search]
     end
-
 end

app/controllers/admin/poll/officers_controller.rb

@@ -29,5 +29,4 @@ class Admin::Poll::OfficersController < Admin::Poll::BaseController
     @officer.destroy!
     redirect_to admin_officers_path
   end
-
 end

app/controllers/admin/poll/shifts_controller.rb

@@ -1,5 +1,4 @@
 class Admin::Poll::ShiftsController < Admin::Poll::BaseController
-
   before_action :load_booth
   before_action :load_officer