--------------------
**Added**
* Ability to create, edit, and send drafts
* Docstrings and full test coverage
* Proper documentation via Sphinx
**Changed**
* ``DEFAULT_MESSAGE_STATUSES`` is now just ``[ "sent", "sending" ]`` and no longer includes failed-to-send messages.
**Deprecated**
* Removed ``Session.count_sent_messages`` and ``Session.get_sent_messages``, since the change to ``DEFAULT_MESSAGE_STATUSES`` makes them redundant.