QRCode.terminal() should write to the terminal by default

[heuer]

IMO it makes almost no sense that QRCode.terminal() returns a string. The string is in almost all cases printed anyway.

Changing the behaviour would break backward compatibility, though.

Options:

• Change terminal() in a backward incompatible way
• Introduce another method like "term()" which utilizes sys.stdout, deprecate and finally remove terminal()

The latter may be cleaner since the user gets a warning and it allows to remove the module_color and background arguments which have a dubious use, too

[heuer]

Initial work in https://github.com/heuer/pyqrcode/commit/bd38ae469c89a9d32c0a708f3e7cce2dc608f8fc

[heuer]

Fixed with release 1.3.0