Running the update script update-app-ng-deps is providing TypeScript as dependency

Running the update script `update-app-ng-deps` is providing TypeScript as a dependency instead as a **devDependency**

Steps to reporduce:

- Create ng app
```
tns create my-app --ng
```

- Run the update script
```
 ./node_modules/.bin/update-app-ng-deps
```

Result: the `typescript` is installed as a `dependency` instead as `devDependency`

Using:
NPM 6.6.0
Node 10.15.0