Rename `symoro-bin` to `symoro-bin.py`

Rename `symoro-bin` python script to `symoro-bin.py`. This is so that
the script is detected as a python script in Windows (Windows requires
the file extension for detection).

Additionally, a symoblic link -- `symoro-bin` pointing to
`symoro-bin.py` is introduced for non Windows systems.
Update `setup.py`

Update `setup.py` to reflect the new "binary" script for windows.