React: fix warnings

package.json

@@ -83,7 +83,7 @@
     "clean": "node ./bin/clean.js",
     "open-config": "node ./bin/open-config.js",
     "package": "node ./bin/package.js",
-    "start": "electron .",
+    "start": "jsx --es6module src/ build/ && electron .",
     "test": "standard && node ./bin/check-deps.js",
     "update-authors": "./bin/update-authors.sh"
   }