Resize browser window to fit content

[tbostic32]

Instead of specifying a window size in the config, can we tell the browser to resize to fit contents? This way we don't have to worry about the height we specified not being tall enough for some states of the page.

If we go down this route, it would be nice to have the option to manually set it WINDOW_SIZE = (1500, 3500) or automatically resize it (as suggested above) with WINDOW_SIZE = "auto".