List the packages currently installed in a dict::

        {'<package_name>': '<version>'}

    root
        use root as top level directory (default: "/")

    CLI Example:

    .. code-block:: bash

        salt '*' lowpkg.list_pkgs

def list_pkgs(*packages, **kwargs):
    '''
    List the packages currently installed in a dict::

        {'<package_name>': '<version>'}

    root
        use root as top level directory (default: "/")

    CLI Example:

    .. code-block:: bash

        salt '*' lowpkg.list_pkgs
    '''
    pkgs = {}
    cmd = ['rpm']
    if kwargs.get('root'):
        cmd.extend(['--root', kwargs['root']])
    cmd.extend(['-q' if packages else '-qa',
                '--queryformat', r'%{NAME} %{VERSION}\n'])
    if packages:
        cmd.extend(packages)
    out = __salt__['cmd.run'](cmd, output_loglevel='trace', python_shell=False)
    for line in salt.utils.itertools.split(out, '\n'):
        if 'is not installed' in line:
            continue
        comps = line.split()
        pkgs[comps[0]] = comps[1]
    return pkgs