Install a pkg file

    Args:
        pkg (str): The package to install
        target (str): The target in which to install the package to
        store (bool): Should the package be installed as if it was from the
                      store?
        allow_untrusted (bool): Allow the installation of untrusted packages?

    Returns:
        dict: A dictionary containing the results of the installation

    CLI Example:

    .. code-block:: bash

        salt '*' macpackage.install test.pkg

def install(pkg, target='LocalSystem', store=False, allow_untrusted=False):
    '''
    Install a pkg file

    Args:
        pkg (str): The package to install
        target (str): The target in which to install the package to
        store (bool): Should the package be installed as if it was from the
                      store?
        allow_untrusted (bool): Allow the installation of untrusted packages?

    Returns:
        dict: A dictionary containing the results of the installation

    CLI Example:

    .. code-block:: bash

        salt '*' macpackage.install test.pkg
    '''
    if '*.' not in pkg:
        # If we use wildcards, we cannot use quotes
        pkg = _quote(pkg)

    target = _quote(target)

    cmd = 'installer -pkg {0} -target {1}'.format(pkg, target)
    if store:
        cmd += ' -store'
    if allow_untrusted:
        cmd += ' -allowUntrusted'

    # We can only use wildcards in python_shell which is
    # sent by the macpackage state
    python_shell = False
    if '*.' in cmd:
        python_shell = True

    return __salt__['cmd.run_all'](cmd, python_shell=python_shell)