Kill trailing whitespace in ruby files

app/logical/session_creator.rb

@@ -1,6 +1,6 @@
 class SessionCreator
   attr_reader :session, :cookies, :name, :password, :remember
-  
+
   def initialize(session, cookies, name, password, remember)
     @session = session
     @cookies = cookies
@@ -8,17 +8,17 @@ class SessionCreator
     @password = password
     @remember = remember
   end
-  
+
   def authenticate
     if User.authenticate(name, password)
       user = User.find_by_name(name)
       user.update_column(:last_logged_in_at, Time.now)
-      
+
       if remember.present?
         cookies.permanent.signed[:user_name] = user.name
         cookies.permanent[:password_hash] = user.bcrypt_cookie_password_hash
       end
-      
+
       session[:user_id] = user.id
       return true
     else