Bump copyfiles from 1.2.0 to 2.0.0

Bumps [copyfiles](https://github.com/calvinmetcalf/copyfiles) from 1.2.0 to 2.0.0.
- [Release notes](https://github.com/calvinmetcalf/copyfiles/releases)
- [Commits](https://github.com/calvinmetcalf/copyfiles/compare/v1.2.0...v2.0.0)

Signed-off-by: dependabot[bot] <support@dependabot.com>

packages/0x.js/package.json

@@ -81,7 +81,7 @@
         "chai": "^4.0.1",
         "chai-as-promised": "^7.1.0",
         "chai-bignumber": "^2.0.1",
-        "copyfiles": "^1.2.0",
+        "copyfiles": "^2.0.0",
         "dirty-chai": "^2.0.1",
         "json-loader": "^0.5.4",
         "make-promises-safe": "^1.1.0",