Upgrade typescript to 4.0.3 (#598)

Author: yavorona

packages/event-processor/package-lock.json

@@ -43,13 +43,13 @@
     "@optimizely/js-sdk-utils": "^0.4.0"
   },
   "devDependencies": {
-    "@react-native-community/netinfo": "^5.9.4",
     "@react-native-community/async-storage": "^1.2.0",
+    "@react-native-community/netinfo": "^5.9.4",
     "@types/jest": "^24.0.9",
     "jest": "^23.6.0",
     "jest-localstorage-mock": "^2.4.0",
     "ts-jest": "^23.10.5",
-    "typescript": "3.3.3333"
+    "typescript": "^4.0.3"
   },
   "peerDependencies": {
     "@react-native-community/netinfo": "5.9.4",