Execute command does not execute on all tasks in a service

[aallawala]

when issuing a broadside execute --all command to a particular service that includes more than one task and two or more tasks are found on the same EC2 instance, broadside will only perform the execute command on one of the multiple tasks on the same ec2 instance. A workaround at the moment is to define the placement strategy of the service to distinctInstance. (This will require recreating the service in ECS before deploying and executing a command against.)

Fixing how we target the tasks from looking at ip addresses to looking at the tasks themselves will solve the issue.