Update Readme

It's not necessary to install all the dev dependencies recursively. This could go into the GBs.

README.md

@@ -207,9 +207,9 @@ var showdown    = require('showdown'),
 
 ## Tests
 
-A suite of tests is available which require node.js.  Once node is installed, run the following command from the project root to install the development dependencies:
+A suite of tests is available which require node.js.  Once node is installed, run the following command from the project root to install the dependencies:
 
-    npm install --dev
+    npm install
 
 Once installed the tests can be run from the project root using: