script/repl does not exist, update README

Author: fugalh

README.markdown

@@ -18,7 +18,7 @@ will be.
 * Make sure you have Java installed.
 * Make sure you have [leiningen](http://github.com/technomancy/leiningen) installed.
 * Run `lein deps` to install all the dependent libraries.
-* Run `script/repl` to launch a repl.
+* Run `lein repl` to launch a repl.
 
 # Want more Clojure Practice?