Add script for rebuilding fixtures

Author: adamwathan

package.json

@@ -20,6 +20,7 @@
   "scripts": {
     "prebabelify": "rimraf lib",
     "babelify": "babel src --out-dir lib --copy-files",
+    "rebuild-fixtures": "npm run babelify && babel-node scripts/rebuildFixtures.js",
     "prepare": "npm run babelify && babel-node src/build.js",
     "style": "eslint .",
     "test": "jest && eslint ."