While *some* systems alias python to python3 nowdays, this is
not true for eveything. Especially systems that can potentially
offer both python2 and python3.
According to both PEP 394 and PEP 441 its recommended to always
add the 3 in the shebang.
The existing post-install shell script will most likely not work on
Visual Studio builds as there is normally no shell interpreter installed
on the system where the build is done, but the build is normally done in
a standard Windows cmd.exe console.
Instead, use a Python script so that it will work on the platforms that
Python supports.
