chore(deps): update dependency @types/chai to v4.2.12

Author: renovate-bot

package-lock.json

@@ -64,7 +64,7 @@
   "devDependencies": {
     "@commitlint/cli": "8.2.0",
     "@commitlint/config-angular": "8.2.0",
-    "@types/chai": "4.2.4",
+    "@types/chai": "4.2.12",
     "@types/mocha": "5.2.7",
     "@types/node": "11.15.10",
     "@types/node-sass": "4.11.0",