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

Closes #43

Author: greenkeeper[bot]

package.json

@@ -66,7 +66,7 @@
         "@types/ua-parser-js": "^0.7.32",
         "chai": "^4.1.2",
         "clean-webpack-plugin": "^2.0.0",
-        "copy-webpack-plugin": "^4.5.2",
+        "copy-webpack-plugin": "^6.0.1",
         "glob": "^7.1.2",
         "mocha": "^6.0.0",
         "supertest": "^4.0.0",