OutStream.isatty

I'm using jupyter notebook and `sys.stdout` is `ipykernel.iostream.OutStream`.
And `sys.stdout.isatty()` is False.

Since the output is interactive/terminal-like, I expect it to be true. Also see [comments in cpython](https://github.com/python/cpython/blob/master/Lib/_pyio.py#L469).

Can this be changed? This should be simply two lines of code.