[Build] Update yarn build script

package.json

@@ -17,9 +17,9 @@
         "clean": "rm -Rf output node_modules",
         "clean-js": "rm -Rf node_modules",
         "clean-ps": "rm -Rf output",
-        "server": "serve dist",
+        "server": "serve -l 8000 dist",
         "server-ssl": "ssl-serve --ssl dist",
-        "build": "spago build && pulp browserify --skip-compile -t dist/bundle.js --src-path output",
+        "build": "spago bundle-app --main Main --to dist/bundle.js",
         "prod": "yarn prod:compile && yarn prod:dce && yarn prod:bundle && yarn prod:pack",
         "prod:compile": "pulp build -- -g corefn",
         "prod:dce": "zephyr -f Main.main",