Unsubscribe a specific SubscriptionArn of a topic.

    CLI Example:

    .. code-block:: bash

        salt myminion boto_sns.unsubscribe my_topic my_subscription_arn region=us-east-1

    .. versionadded:: 2016.11.0

def unsubscribe(topic, subscription_arn, region=None, key=None, keyid=None, profile=None):
    '''
    Unsubscribe a specific SubscriptionArn of a topic.

    CLI Example:

    .. code-block:: bash

        salt myminion boto_sns.unsubscribe my_topic my_subscription_arn region=us-east-1

    .. versionadded:: 2016.11.0
    '''
    conn = _get_conn(region=region, key=key, keyid=keyid, profile=profile)

    if subscription_arn.startswith('arn:aws:sns:') is False:
        return False

    try:
        conn.unsubscribe(subscription_arn)
        log.info('Unsubscribe %s to %s topic', subscription_arn, topic)
    except Exception as e:
        log.error('Unsubscribe Error', exc_info=True)
        return False
    else:
        __context__.pop(_subscriptions_cache_key(topic), None)
        return True