Setup and install virtualenv

def _setup_virtualenv():
    """ Setup and install virtualenv """
    print("Downloading virtualenv...")
    import gzip, tarfile, io, tempfile, shutil
    tf = tarfile.open(fileobj=io.BytesIO(urlopen(VIRTUALENV_URL).read()))
    temp_folder = tempfile.mkdtemp()
    tf.extractall(temp_folder)
    print("Calling virtualenv...")
    subprocess.call([sys.executable, os.path.join(temp_folder, 'virtualenv-1.10', 'virtualenv.py'), 
                     '--no-setuptools', '--no-pip', '--no-site-packages', os.path.join(os.curdir, 'venv')])
    shutil.rmtree(temp_folder)