added comment

lib/jam_ruby/models/user.rb

@@ -50,6 +50,8 @@ module JamRuby
     has_many :received_invitations, :foreign_key => "receiver_id", :inverse_of => :receiver, :class_name => "JamRuby::Invitation"
     has_many :sent_invitations, :foreign_key => "sender_id", :inverse_of => :sender, :class_name => "JamRuby::Invitation"
 
+
+    # This causes the authenticate method to be generated (among other stuff)
     has_secure_password
 
     before_save { |user| user.email = email.downcase }