Removing go to page methods

This is for issue https://github.com/mozilla/remo-tests/issues/88
Please test this with <code>self.maximize_window()</code>, if you get some fails it's because of bug https://bugzilla.mozilla.org/show_bug.cgi?id=911734
Add the maximize window here: https://github.com/mozilla/remo-tests/blob/master/pages/home.py#L24