'Remove an existing egress rule from an existing VPC security
group.  You need to pass in an ip_protocol, from_port and
to_port range only if the protocol you are using is
port-based. You also need to pass in either a src_group_id or
cidr_ip.
:type group_name: string
:param group_id:  The name of the security group you are removing
the rule from.
:type ip_protocol: string
:param ip_protocol: Either tcp | udp | icmp | -1
:type from_port: int
:param from_port: The beginning port number you are disabling
:type to_port: int
:param to_port: The ending port number you are disabling
:type src_group_id: src_group_id
:param src_group_id: The source security group you are
revoking access to.
:type cidr_ip: string
:param cidr_ip: The CIDR block you are revoking access to.
See http://goo.gl/Yj5QC
:type dry_run: bool
:param dry_run: Set to True if the operation should not actually run.
:rtype: bool
:return: True if successful.'

def revoke_security_group_egress(self, group_id, ip_protocol, from_port=None, to_port=None, src_group_id=None, cidr_ip=None, dry_run=False):

    params = {}
    if group_id:
        params['GroupId'] = group_id
    if ip_protocol:
        params['IpPermissions.1.IpProtocol'] = ip_protocol
    if (from_port is not None):
        params['IpPermissions.1.FromPort'] = from_port
    if (to_port is not None):
        params['IpPermissions.1.ToPort'] = to_port
    if (src_group_id is not None):
        params['IpPermissions.1.Groups.1.GroupId'] = src_group_id
    if cidr_ip:
        params['IpPermissions.1.IpRanges.1.CidrIp'] = cidr_ip
    if dry_run:
        params['DryRun'] = 'true'
    return self.get_status('RevokeSecurityGroupEgress', params, verb='POST')
