Does not work with Twilio 6.x.x

[jpgavin]

When installing Twilio (pip install twilio), as of today, the Twilio version is 6.0.0, which uses a slightly different import and initialization. As detailed in Twilio's migration guide, the following changes are required in ge-checker-cron.py

1. from twilio.rest import TwilioRestClient needs to change to from twilio.rest import Client
2. client = TwilioRestClient(account_sid, auth_token) needs to change to client = Client(account_sid, auth_token)