Updates self.data from series data

        Parameters
        ----------
         * series_data: dict
        \tKey value pairs for self.data, which correspond to chart attributes

def update(self, series_data):
        """Updates self.data from series data

        Parameters
        ----------
         * series_data: dict
        \tKey value pairs for self.data, which correspond to chart attributes

        """

        for key in series_data:
            try:
                data_list = list(self.data[key])
                data_list[2] = str(series_data[key])
                self.data[key] = tuple(data_list)
            except KeyError:
                pass