fix(demo): updated typescript to v3.2.4

Author: AnthonyNahas

package-lock.json

@@ -120,7 +120,7 @@
     "travis-status": "^3.0.1",
     "tsickle": "^0.34.3",
     "tslint": "~5.12.1",
-    "typescript": "~3.1.6",
+    "typescript": "~3.2.4",
     "webpack": "^4.29.6",
     "webpack-cli": "^3.2.3",
     "webpack-dev-middleware": "^3.6.1",