build(deps-dev): Bump @types/chai from 4.2.6 to 4.2.7

Bumps [@types/chai](https://github.com/DefinitelyTyped/DefinitelyTyped/tree/HEAD/types/chai) from 4.2.6 to 4.2.7.
- [Release notes](https://github.com/DefinitelyTyped/DefinitelyTyped/releases)
- [Commits](https://github.com/DefinitelyTyped/DefinitelyTyped/commits/HEAD/types/chai)

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

package.json

@@ -2,7 +2,7 @@
   "name": "stryker-parent",
   "private": true,
   "devDependencies": {
-    "@types/chai": "4.2.6",
+    "@types/chai": "4.2.7",
     "@types/chai-as-promised": "7.1.2",
     "@types/glob": "^7.1.0",
     "@types/istanbul": "^0.4.29",