fix(package.json): bind web server only to localhost

It's better to bind to localhost only during development, since it improves security.
It also avoids a pesky warning under Mac OS.

Closes #165

Author: Paul Melnikow

package.json

@@ -16,7 +16,7 @@
     "postinstall": "bower install",
 
     "prestart": "npm install",
-    "start": "http-server -p 8000",
+    "start": "http-server -a localhost -p 8000",
 
     "pretest": "npm install",
     "test": "karma start test/karma.conf.js",