Replace check_output which appear in python2.7

    '''

    from os import getcwd, chdir, devnull

    from os.path import dirname

    from subprocess import check_output, CalledProcessError

    from subprocess import Popen, PIPE

    from sys import argv

    version = ""

    cwd = getcwd()

    try:

        chdir(dirname(argv[0]))

        version = check_output(["git", "describe", "--tags", "--always" ],

        process = Popen(["git", "describe", "--tags", "--always" ],

                        stdout=PIPE,

                        stdin=open(devnull, 'rb'),

                               stderr=open(devnull, "wb")).strip()

                        stderr=open(devnull, "wb"))

        version = process.communicate()[0].strip()

        if len(version) > 0:

            version = "-" + version

    except (OSError, CalledProcessError):

    except OSError:

        pass

    finally:

        chdir(cwd)