Python >= 2.7

[DimitriPapadopoulos]

Do the current Prerequisites still include Python 2.7?

For Linux, two software must be installed : Python (version >= 2.7) and Singularity (version > 3.6).

[denisri]

Not exactly actually. Releases 5.0.x could use either python 2 or 3, and 5.1.x require python3. We must clarify it in the doc, thanks.