agents acceptance tests.

CreateExternalNetwork will create an external network.

CreatePortWithSecurityGroup will create a port with a security group attached.

CreateSecurityGroup will create a security group with a random name.

CreateSecurityGroupRule will create a security group rule with a random name and random port between 80 and 99.

DeleteSecurityGroup will delete a security group of a specified ID.

DeleteSecurityGroupRule will delete a security group rule of a specified ID.