add .irbrc so that one can run it instantanious

.irbrc

@@ -0,0 +1,12 @@
+$:.unshift File.expand_path('lib')
+
+require 'asin'
+
+ASIN::Configuration.configure do |config|
+  config.secret        = ENV['ASIN_SECRET']
+  config.key           = ENV['ASIN_KEY']
+  config.associate_tag = ENV['ASIN_TAG']
+end
+
+@client = ASIN::Client.instance
+