Use ActiveSupport.on_load for initialization (#118)

Defer the inclusion until after ActiveRecord has been fully loaded, improving booting performance and following Rails best practices (#118)

Author: shashankdass

lib/rails-settings.rb

@@ -3,11 +3,13 @@
 require 'rails-settings/base'
 require 'rails-settings/scopes'
 
-ActiveRecord::Base.class_eval do
-  def self.has_settings(*args, &block)
-    RailsSettings::Configuration.new(*args.unshift(self), &block)
+ActiveSupport.on_load(:active_record) do
+  ActiveRecord::Base.class_eval do
+    def self.has_settings(*args, &block)
+      RailsSettings::Configuration.new(*args.unshift(self), &block)
 
-    include RailsSettings::Base
-    extend RailsSettings::Scopes
+      include RailsSettings::Base
+      extend RailsSettings::Scopes
+    end
   end
-end
+end