Test DIRACOS as a User

If you want to test DIRACOS in a DIRAC installation, it is enough to do the following:

https://raw.githubusercontent.com/DIRACGrid/DIRAC/integration/Core/scripts/dirac-install.py
chmod +x dirac-install.py
./dirac-install.py -r v6r20 --dirac-os --dirac-os-version=0.0.5