chore(package.json): explicitly list domain and port arguments in npm start

A developer working on a remote server will want to change the IP
address which `npm start` serves on. A developer working on a machine
which is already using port 8000 will want to change the port. By
listing those arguments explicitly, it angular-phonecat makes it easier
for developers who are unfamiliar with npm and are working through the
tutorial to see that they can do so. This should be accompanied by a
sentence in the documentation.

Closes #191

Author: amfarrell

package.json

@@ -19,7 +19,7 @@
     "postinstall": "bower install",
 
     "prestart": "npm install",
-    "start": "http-server -p 8000",
+    "start": "http-server --domain 0.0.0.0 --port 8000",
 
     "pretest": "npm install",
     "test": "node node_modules/karma/bin/karma start test/karma.conf.js",