chore(deps-dev): update mocha requirement from 6.1.4 to 6.2.0

Updates the requirements on [mocha](https://github.com/mochajs/mocha) to permit the latest version.
- [Release notes](https://github.com/mochajs/mocha/releases)
- [Changelog](https://github.com/mochajs/mocha/blob/master/CHANGELOG.md)
- [Commits](mochajs/mocha@v6.1.4...v6.2.0)

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

Author: dependabot-preview[bot]

package.json

@@ -24,7 +24,7 @@
     "eslint": "4.19.0",
     "eslint-config-airbnb-base": "12.1.0",
     "eslint-plugin-import": "2.18.0",
-    "mocha": "6.1.4"
+    "mocha": "6.2.0"
   },
   "keywords": [
     "curl",