Feature Request: Upload schema using a URL

[mpmenne]

I'm currently using twilio/autopilot-cli to perform some automation work specifically around twilio autopilot:update --schema. My schemas are stored in S3, so it would be very convenient to be able to pass a link to the command like this:

twilio autopilot:update --schema http://some-bucket.s3.amazonaws.com/my-bot-schema.json

I'm sorry that I am not able to submit a PR at this time, but I'm curious if anyone else would be interested in this functionality as well. Thank you for the handy CLI upload!