roll back typescript version

package.json

@@ -50,7 +50,7 @@
     "protractor": "~5.4.2",
     "ts-node": "~8.0.2",
     "tslint": "~5.12.1",
-    "typescript": "3.3.3",
+    "typescript": "3.2.4",
     "@angular-devkit/build-angular": "~0.13.1"
   }
 }