Node.js - Convert Phone number to E164 format

1. We need a node.js script that will take a phone number and convert to E164 format

2. For example convert '03456004903' to: '+443456004903'

3. You can test the required functionality using:
http://rawgit.com/googlei18n/libphonenumber/master/javascript/i18n/phonenumbers/demo-compiled.html

4. The default country code is 'GB'

5. To make it easy to convert, we can use:
https://www.npmjs.com/package/google-libphonenumber

6. Please create a free twilio account, and save the script as a twilio function using:
https://www.twilio.com/functions

Thanks!
Extra notes: