Better way of handling the authorization tokens

[bstoilov]

Currently a registry is used to store the cookies and some headers.

This is hard to read and maintain.

A much simpler solution is to keep cookies in file and read them like plain string.

    def _load_headers(self):
        cookies = self.registry.get(Registry.Key.COOKIES)
        csrftoken = ''
        cookie_str = ''
        for c in cookies:
            if c.name == 'csrftoken':
                csrftoken = c.value
            cookie_str += c.name + '=' + c.value + '; '
        cookie_str = cookie_str.strip()

        headers = {
            'cookie': cookie_str,
            'x-csrftoken': csrftoken,
            'user-agent': AGENT_STRING
        }

        return headers

this is all the data we need to make requests

After this change all requests can be simplified to the following structure

        options = {
        }

        data_obj = {
            'options': options,
            'context': {}
        }

        data = {
            'source_url': '/pin/{}/'.format(pin_id),
            'data': json.dumps(data_obj)
        }

        headers = self._load_headers()
        return requests.post(url=url, headers=headers, data=data)

[bstoilov]

This is addressed in this PR:

#20