Decode comands output into strings for Python 3 compatibility
Decode comands output into strings for Python 3 compatibility

On Python 3, the return of check_output is of type bytes, and these need
to be decoded in order to be used as regular strings.

Changelog: None

Signed-off-by: Lluis Campos <9244cb41c39addfc5cf236920b776ea2820513d0@northern.tech>

pasinskim/integration,pasinskim/integration,pasinskim/integration