Added preferences for click amount and valid days on digital links. Tests for authorization are now running

lib/spree/spree_digital_configuration.rb

@@ -0,0 +1,6 @@
+module Spree
+  class SpreeDigitalConfiguration < Preferences::Configuration
+    preference :authorized_clicks,  :integer, :default => 3
+    preference :authorized_days,    :integer, :default => 2
+  end
+end