Kill trailing whitespace in ruby files

app/presenters/wiki_page_presenter.rb

@@ -1,26 +1,26 @@
 class WikiPagePresenter
   attr_reader :wiki_page
-  
+
   def initialize(wiki_page)
     @wiki_page = wiki_page
   end
-  
+
   def excerpt
     wiki_page.body
   end
-  
+
   def blurb
     excerpt.try(:gsub, /<.+?>/, "")
   end
-  
+
   def consequent_tag_aliases
     @consequent_tag_aliases ||= TagAlias.where("consequent_name = ?", wiki_page.title)
   end
-  
+
   def antecedent_tag_alias
     @antecedent_tag_alias ||= TagAlias.find_by_antecedent_name(wiki_page.title)
   end
-  
+
   # Produce a formatted page that shows the difference between two versions of a page.
   def diff(other_version)
     pattern = Regexp.new('(?:<.+?>)|(?:[0-9_A-Za-z\x80-\xff]+[\x09\x20]?)|(?:[ \t]+)|(?:\r?\n)|(?:.+?)')