fix test setup

Author: sgratzl

package-lock.json

@@ -24,6 +24,7 @@
   "devDependencies": {
     "@babel/core": "^7.2.2",
     "@babel/preset-env": "^7.2.0",
+    "babel-core": "^7.0.0-bridge.0",
     "babel-jest": "^23.6.0",
     "eslint": "^5.10.0",
     "jest": "^23.6.0",
@@ -42,6 +43,7 @@
     "lint": "eslint src",
     "pretest": "npm run lint",
     "test": "jest",
+    "test:watch": "jest --watch",
     "build:dev": "rollup -c -i src/index.js",
     "build:prod": "npm run build:dev && uglifyjs build/Chart.Hierarchical.js -c -m -o build/Chart.Hierarchical.min.js",
     "prebuild": "npm run clean && npm test",