`update-notifier` persist its update check results in a file, which is
then read when running again the application.
If this file gets written when the application is being run as root, we
get ugly EPERM issues.
For this we use the `update-notifier` module with its default settings.
This module will print a nice banner prompting the user to run the
corresponding npm command to update.
- Add helpers.confirm() to abstract the process of asking for
confirmation.
- Add helpers.selectDeviceType() to abstract the form needed to ask for
device types.
The functions on this module are reused by app actions.
