Merge pull request #239 from davidyaha/dependabot/npm_and_yarn/typescript-4.0.2

Bump typescript from 3.1.1 to 4.0.2

Author: davidyaha

package-lock.json

@@ -62,7 +62,7 @@
     "remap-istanbul": "^0.12.0",
     "simple-mock": "^0.8.0",
     "tslint": "^5.8.0",
-    "typescript": "^3.1.1"
+    "typescript": "^4.0.2"
   },
   "optionalDependencies": {
     "ioredis": "^4.6.3"