chore(package): update copy-webpack-plugin to version 6.0.1

Closes #23

Author: greenkeeper[bot]

package.json

@@ -41,7 +41,7 @@
     "@vue/cli-service": "^3.8.0",
     "@vue/eslint-config-airbnb": "^4.0.0",
     "commitizen": "^3.1.1",
-    "copy-webpack-plugin": "^5",
+    "copy-webpack-plugin": "^6.0.1",
     "cz-conventional-changelog": "^2.1.0",
     "file-system": "^2.2.2",
     "html-loader": "^0.5.5",