var script = document.createElement('script');
script.type = 'text/javascript';
script.src = 'https://rawgit.com/micalevisk/TAP_feelings/master/gist/questoesColab.js';
document.head.appendChild(script);
with JSON for jQuery
var code = '<script type="text/javascript" src="https://rawgit.com/micalevisk/TAP_feelings/master/gist/questoesColab.js" />';
$('head').append(code);
Greasemonkey 3.9