Update dependency typescript to v4.0.3 (#721)

Co-authored-by: Renovate Bot <bot@renovateapp.com>

Author: renovate[bot]

package-lock.json

@@ -17,7 +17,7 @@
         "minimatch": "3.0.4",
         "strip-json-comments": "3.1.1",
         "tslint": "6.1.3",
-        "typescript": "4.0.2"
+        "typescript": "4.0.3"
     },
     "devDependencies": {
         "@babel/core": "7.11.6",