Fix CR/NL error for python on windows

[simonliedl]

On Windows, python replaces newline with carriage-return + newline. Therefore the git credentials don't work, as they appear as "username\r".

They only solution i found is to output a string converted to bytes in binary mode.

[z00nx]

@simonliedl thanks for the pull request.
Can you share more details of your environment including windows versions, python versions ?

[simonliedl]

@z00nx of course, sorry for not sharing in the first place:

-> % git --version
git version 2.9.1
-> % python --version
Python 3.6.2

Windows version:
Microsoft Windows 10 Pro 10.0.17134 Build 17134