The decrypt method of the message class now returns a tuple of three elements
instead of four:
* message
* keys
* flags
There is no more rating among the results, as the rating is now a property of
the message -- and can be easily accessed as message.rating .
Update examples and tests.
so that they all can run with just one pytest command, they can be
integrated with python test command and with tox and they can be
run separately with different python versions.
Luca Saiu