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

Closes #93

Author: greenkeeper[bot]

package.json

@@ -66,7 +66,7 @@
     "codelyzer": "^4.5.0",
     "commitplease": "3.2.0",
     "conventional-github-releaser": "2.0.2",
-    "copy-webpack-plugin": "^5.0.2",
+    "copy-webpack-plugin": "^6.0.1",
     "core-js": "2.5.7",
     "css-loader": "^1.0.0",
     "cssnano": "^4.1.10",