added ability update success flash

Author: Oaphi

app/controllers/abilities_controller.rb

@@ -19,6 +19,7 @@ def edit; end
   def update
     if @ability.update(ability_update_params)
       do_delete_draft(current_user, URI(request.referer || '').path)
+      flash[:success] = I18n.t('abilities.success.update_generic')
       redirect_to ability_path(id: @ability.internal_id)
     else
       render :edit, status: :bad_request

config/locales/strings/en.abilities.yml

@@ -5,3 +5,6 @@ en:
       Description
     unsaved_changes_confirmation: >
       Any unsaved changes will be lost. Are you sure?
+    success:
+      update_generic: >
+        Ability successfully updated.