Aiorequestful

Fixed
-----
* Removed debug print statement

Fixed
-----
* Bug in :py:meth:`get_iterator` causing :py:class:`.RequestInfo` objects
to iterate its properties instead of itself

Changed
-------
* Update upstream dependency versions

Fixed
-----
* Typing in :py:class:`.RequestHandler`
* Added missing python-dateutil dependency

Changed
-------
* Moved :py:class:`.RequestHandler` to base of package in request.py
* Moved all :py:class:`.Timer` implementations to base of package in timer.py
* Moved all request exceptions to base of package in exception.py

Documentation
-------------
* Finalise writing guides

Added
-----
* Raise an exception on :py:meth:`.RequestHandler.request` when called and the session is closed.

Documentation
-------------
* Expand README to complete all placeholder sections