Wrong input parameters for Discussions_by_author_before_date in Docstring and get_discussions

[espoem]

Expected behaviour

As per the steem documentation of the API method (see https://developers.steem.io/apidefinitions/#tags_api.get_discussions_by_author_before_date, the input parameters should be:

• author
• start_permlink
• before_date
• limit

The correct parameters should be described in the docstring of the method and passed in the get_discussions method of Discussions class.

Actual behaviour

Although the method definition has the correct parameters, the docstring describes the parameters as instance of Query class. https://github.com/holgern/beem/blob/master/beem/discussions.py#L205

Furthermore, incorrect query parameter is passed in get_discussions method. https://github.com/holgern/beem/blob/master/beem/discussions.py#L113

Additional notes

The Discussions_by_author_before_date method can't get parameters from the instance of Query because the class does not have all needed parameters such as before_date and author.