Check to see if policy exists.

    CLI Example:

    .. code-block:: bash

        salt myminion boto_iam.instance_profile_exists myiprofile

def policy_version_exists(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)

    policy_arn = _get_policy_arn(policy_name, region, key, keyid, profile)
    try:
        conn.get_policy_version(policy_arn, version_id)
        return True
    except boto.exception.BotoServerError:
        return False