'Gets remote HTML page for conversion
Downloads HTML page from `url` as a string and passes it to the
`from_string` method. Also sets `self.root_url` and `self.relative_url`
for use in importing <link> elements.
Returns self.
>>> p = Pynliner()
>>> p.from_url(\'http://somewebsite.com/file.html\')
<Pynliner object at 0x26ac70>'

def from_url(self, url):

    self.url = url
    self.relative_url = ('/'.join(url.split('/')[:(-1)]) + '/')
    self.root_url = '/'.join(url.split('/')[:3])
    self.source_string = self._get_url(self.url)
    return self
