Add publicPath to webpack config to fix dev-server's livereload.

The issue was that the webpack-dev-server seemed to serve the old files
instead of the newly bundled ones.
The explanation of the solution can be found here:
webpack/webpack-dev-server#24 (comment)

webpack.config.js

@@ -5,6 +5,7 @@ module.exports = {
     entry: ['es6-shim', 'zone.js', 'reflect-metadata', './src/boot.ts'],
     output: {
         path: __dirname + "/build",
+        publicPath: "/build/",
         filename: "uhk.js"
     },
     devtool: 'source-map',
@@ -48,4 +49,4 @@ module.exports = {
         )
     ]
 
-}
+}