Azure: Increase verbosity for Tox task
    
    This allows to debug issues happened during packages installation:
    
    > -v, --verbose     increase verbosity of reporting output.
    -vv mode turns off output redirection for package installation,
    above level two verbosity flags are passed through to pip (with two less
    level) (default: 0)
    
    Signed-off-by: Stanislav Levin <slev@altlinux.org>
    Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>