make minor linting changes and update the evil test about number of pages

app/models/form/sales/pages/about_staircase.rb

@@ -5,7 +5,7 @@ class Form::Sales::Pages::AboutStaircase < ::Form::Page
     @header = "About the staircasing transaction"
     @depends_on = [{
       "staircase" => 1,
-      "joint_purchase?" => joint_purchase
+      "joint_purchase?" => joint_purchase,
     }]
   end
 

app/models/form/sales/questions/staircase_owned.rb

@@ -2,7 +2,7 @@ class Form::Sales::Questions::StaircaseOwned < ::Form::Question
   def initialize(id, hsh, page, joint_purchase:)
     super(id, hsh, page)
     @id = "stairowned"
-    @check_answer_label = "Percentage the buyer#{'s' if joint_purchase} now own#{'s' if !joint_purchase} in total"
+    @check_answer_label = "Percentage the buyer#{'s' if joint_purchase} now own#{'s' unless joint_purchase} in total"
     @header = "What percentage of the property #{joint_purchase ? 'do the buyers' : 'does the buyer'} now own in total?"
     @type = "numeric"
     @width = 5