Added implementation in common lisp with unit-test

- added the existing implementation in common lisp with system-definition
- added a parachute-unit-test
- added a description for setup and running the unit-tests
- added a description for stubbing and mocking with cl-mock

common-lisp-parachute/source/package.lisp

@@ -0,0 +1,14 @@
+;;;; package.lisp
+
+(defpackage :gilded-rose
+  (:use :cl)
+  (:export :run-gilded-rose
+	   :gilded-rose
+	   :update-quality
+	   :items
+	   :item
+           :name
+	   :sell-in
+	   :quality))
+	   
+