Update dependency typescript to v3.9.6

Author: renovate-bot

package-lock.json

@@ -40,7 +40,7 @@
     "tslint": "5.20.1",
     "tslint-clean-code": "0.2.10",
     "tslint-microsoft-contrib": "6.2.0",
-    "typescript": "3.9.5",
+    "typescript": "3.9.6",
     "unibeautify": "0.17.0",
     "csscomb": "4.3.0"
   },