Update package.json

Author: yiiqii

package.json

@@ -17,7 +17,7 @@
     "babel-preset-es2015": "^6.24.1",
     "babel-preset-stage-0": "^6.24.1",
     "clean-webpack-plugin": "^0.1.19",
-    "copy-webpack-plugin": "^4.5.1",
+    "copy-webpack-plugin": "^6.4.1",
     "css-loader": "^0.28.11",
     "eslint": "^4.19.1",
     "eslint-config-standard": "^11.0.0",