adds "build" and "watch" commands to package.json

This allows us to run Gulp from the local `node_modules` directory and
provides a consistent interface for running project-level tasks.

Author: allanlasser

package.json

@@ -36,6 +36,8 @@
     "htmlclean": "^3.0.2"
   },
   "scripts": {
+    "build": "gulp",
+    "watch": "gulp watch",
     "test": "echo \"Error: no test specified\" && exit 1"
   },
   "license": "MIT"