Low down the severity for running os commands

[LanderU]

Before this patch:

    Total issues (by severity):
        Undefined: 0.0
        Low: 13.0
        Medium: 0.0
        High: 4.0

After:

    Total issues (by severity):
        Undefined: 0.0
        Low: 17.0
        Medium: 0.0
        High: 1.0

I've tried to completely remove the issues, even low ones, but, I think you need to add exceptions for these type of calls.

The remaining High issue is in the following piece of code:

• https://github.com/aliasrobotics/RVD/blob/master/rvd_tools/cve/cve.py#L153-L168

I'll let Alias Robotics developers to decide how to proceed here.

Signed-off-by: LanderU lander.usategui@gmail.com

[vmayoral]

Thanks for this!