After Python 2 is getting unsupported, new distros
like CentOS 8 and RHEL8 have stopped providing 'python'
package forcing user to decide which alternative to
use by installing 'python2' or 'python3.x' package
and then setting python alternative.
This change is intended to make using python3 command as
much as possible and use it as default 'python' alternative
where needed.
The final goals motivating this change are:
- stop using python2 as much as possible
- help adding support for CentOS 8 and RHEL8
Change-Id: I1e90db987c0bfa6206c211e066be03ea8738ad3f