Change the gid for a named group

    CLI Example:

    .. code-block:: bash

        salt '*' group.chgid foo 4376

def chgid(name, gid):
    '''
    Change the gid for a named group

    CLI Example:

    .. code-block:: bash

        salt '*' group.chgid foo 4376
    '''
    pre_gid = __salt__['file.group_to_gid'](name)
    if gid == pre_gid:
        return True
    cmd = 'groupmod -g {0} {1}'.format(gid, name)
    __salt__['cmd.run'](cmd, python_shell=False)
    post_gid = __salt__['file.group_to_gid'](name)
    if post_gid != pre_gid:
        return post_gid == gid
    return False