fix: next page of results requests

[kuryaki]

Reported this issue: twilio/twilio-cli#74
It breaks when listing items that have more than one page, nextPageUrl contains the full path, so adding the host to it will create a bad URL

https://messaging.twilio.comhttps://messaging.twilio.com/v1/Services?PageSize=50&Page=1&PageToken=XXXX

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[childish-sambino]

I don’t think this works if the next page url is relative. Looks like logic is needed to check if the next page is relative or not.