Bump chai from 4.1.2 to 4.2.0

Bumps [chai](https://github.com/chaijs/chai) from 4.1.2 to 4.2.0.
- [Release notes](https://github.com/chaijs/chai/releases)
- [Changelog](https://github.com/chaijs/chai/blob/master/History.md)
- [Commits](https://github.com/chaijs/chai/compare/4.1.2...4.2.0)

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

package.json

@@ -80,7 +80,7 @@
     "babel-register": "^6.24.1",
     "babili-webpack-plugin": "^0.1.2",
     "cfonts": "^2.4.5",
-    "chai": "^4.0.0",
+    "chai": "^4.2.0",
     "chalk": "^2.1.0",
     "copy-webpack-plugin": "^4.0.1",
     "cross-env": "^5.0.5",