apply StringLiterals cop (remove double quotes, unless there is string interpolation)

app/controllers/admin/supporters_controller.rb

@@ -0,0 +1,19 @@
+module Admin
+  class SupportersController < Admin::BaseController
+    load_and_authorize_resource :conference, find_by: :short_title
+    load_and_authorize_resource through: :conference
+
+    def index
+      respond_to do |format|
+        format.html
+        format.json { render json: DatatableSupporters.new(@conference.supporter_registrations, view_context) }
+      end
+    end
+
+    def create
+      params[:supporter_registration][:conference_id] = @conference.id
+      SupporterRegistration.create!(params[:supporter_registration])
+      redirect_to(admin_conference_supporters_path(conference_id: @conference.short_title), notice: 'Supporter added')
+    end
+  end
+end