Check to see if policy exists.

    CLI Example:

    .. code-block:: bash

        salt myminion boto_iam.instance_profile_exists myiprofile

def get_policy_version(policy_name, version_id,
               region=None, key=None, keyid=None, profile=None):
    '''
    Check to see if policy exists.

    CLI Example:

    .. code-block:: bash

        salt myminion boto_iam.instance_profile_exists myiprofile
    '''
    conn = _get_conn(region=region, key=key, keyid=keyid, profile=profile)

    try:
        ret = conn.get_policy_version(_get_policy_arn(policy_name,
                            region=region, key=key, keyid=keyid, profile=profile), version_id)
        retval = ret.get('get_policy_version_response', {}).get('get_policy_version_result', {}).get('policy_version', {})
        retval['document'] = _unquote(retval.get('document'))
        return {'policy_version': retval}
    except boto.exception.BotoServerError:
        return None