Website crawler/visitor/cliecker

We need a small tool which will - visit some (given) URLs and - simulate user behavior which is visible on analytics reports: * stay on page (given time) * scroll * search for links/button (with given label) and * click on these So this tool must load images, styles and script. And must be able to render/execute javascript on the page. PhantomJS and CasperJS seem to be the best framework.