Add signUpDate to User params

lib/user.rb

@@ -10,9 +10,10 @@ class User
 
   def to_param
     {
-      email:     email,
-      firstName: first_name,
-      lastName:  last_name
+      email:      email,
+      firstName:  first_name,
+      lastName:   last_name,
+      signUpDate: Date.today
     }
   end
 end