Improve examples in docstrings

[allardbrain]

Ensure that the example method call given in each docstring contains any required parameters as specified by the API documentation. For example, the update_epic_comment() method:

def update_epic_comment(self, epic_id, comment_id, data, **kwargs):
    '''Update a specific Comment on an Epic.
    https://clubhouse.io/api/rest/v3/#Update-Epic-Comment

    Example:
        from clubhouse import ClubhouseClient
        conn = ClubhouseClient(API_KEY)
        conn.update_epic_comment(123, 5, {'description': 'TEST'})
    '''