Update chai requirement from 1.7.1 to 4.2.0

Updates the requirements on [chai](https://github.com/chaijs/chai) to permit the latest version.
- [Release notes](https://github.com/chaijs/chai/releases)
- [Changelog](https://github.com/chaijs/chai/blob/master/History.md)
- [Commits](chaijs/chai@1.7.1...4.2.0)

Signed-off-by: dependabot-preview[bot] <[email protected]>

Author: dependabot-preview[bot]

package.json

@@ -15,7 +15,7 @@
   "devDependencies": {
     "coffee-script": "1.6.3",
     "mocha": "1.11.0",
-    "chai": "1.7.1",
+    "chai": "4.2.0",
     "curl-trace-parser": ""
   },
   "engines": {