prevent jsdom fetching and running external scripts

the page rendered by the headless browser will already contain all modificatios to the page fixed in the HTML/CSS, therefore having jsdom fetch and run the scripts again is a waste of resources and exposes us to the possibility that external scripts will try to do things outside of the jsdom API.

fixes #10
prep v0.1.7
Release v0.1.7.
Merge branch 'master' of github.com:ContentMine/quickscrape