Add .isatty() to PythonQtStdIn

[fepegar]

Hello. I would like an isatty method in stdin as the one in stdout:

pythonqt/src/PythonQtStdOut.cpp

Lines 115 to 117 in 58ccd53

	{"isatty", (PyCFunction)PythonQtStdOutRedirect_isatty, METH_NOARGS,
	"return False since this object is not a tty-like device. Needed for logging framework"
	},

May I open a PR to add it to https://github.com/MeVisLab/pythonqt/blob/master/src/PythonQtStdIn.cpp? This is to follow the advice I was given at Slicer/Slicer#5705 to fix an issue using pip within the 3D Slicer Python console.

[usiems]

Yes, of course, should be straightforward.

[fepegar]

Thanks!