Navigate to the href of the element matching the CSS selector.

    N.B. this does not click the link, but changes the browser's URL.

def follow_link_by_selector(self, selector):
    """
    Navigate to the href of the element matching the CSS selector.

    N.B. this does not click the link, but changes the browser's URL.
    """
    elem = find_element_by_jquery(world.browser, selector)
    href = elem.get_attribute('href')
    world.browser.get(href)