Fix the babel-node error when there is no schema.json

package.json

@@ -3,7 +3,7 @@
   "version": "1.0.0",
   "description": "Relay Starter Kit - Integrated with Relay, GraphQL, Express, ES6/ES7, JSX, Webpack, Babel, Material Design Lite, and PostCSS",
   "scripts": {
-    "start": "babel-node server/index.js",
+    "start": "npm run update && babel-node server/index.js",
     "update": "babel-node server/utils/updateSchema.js",
     "deploy": "NODE_ENV=production webpack --config webpack.production.config.js && NODE_ENV=production npm start"
   },

server/index.js

@@ -36,9 +36,6 @@ if (config.env === 'development') {
   app.use('/', express.static(path.join(__dirname, '../build')));
   app.listen(config.port, () => console.log(`Relay is listening on port ${config.port}`));
 
-  // Update schema.json and schema.graphql
-  updateSchema();
-
   // Watch JavaScript files in the data folder for changes, and update schema.json and schema.graphql
   gaze(path.join(__dirname, 'data/*.js'), (err, watcher) => {
     if (err) console.error('Error: Watching files in data folder');

server/utils/babelRelayPlugin.js

@@ -1 +1,11 @@
-module.exports = require('babel-relay-plugin')(require('../data/schema.json').data);
+var fs = require('fs');
+var path = require('path');
+var jsonFile = path.join(__dirname, '../data/schema.json');
+
+// Read the schema.json file only if it exists, this fixed
+// the problem of using babelRelayPlugin, defined in .babelrc,
+// and running npm run update when the file doesn't exist
+fs.access(jsonFile, fs.F_OK, function(err) {
+  if (!err) module.exports = require('babel-relay-plugin')(require(jsonFile).data);
+});
+