Update dependency typescript to v3.8.3

Author: renovate-bot

package.json

@@ -48,6 +48,6 @@
     "protractor": "5.4.2",
     "ts-node": "8.8.2",
     "tslint": "5.20.1",
-    "typescript": "3.7.5"
+    "typescript": "3.8.3"
   }
 }