python2 is end of life and SONiC is going to support python3. This PR is going to support: 1. Mellanox SONiC platform API python3 support 2. Install both python2 and python3 verson of Mellanox SONiC platform API or pmon and host side
* Implement part of PSU related APIs including get_status(), get_presence() Signed-off-by: Kevin Wang <kevinw@mellanox.com>