add support for setting tags on newly created task definitions

[nwsparks]

It would be helpful to be able to define tags when deploying using ecs-deploy.

We use this tool to coordinate deployments, but Terraform to create the initial task definition. It would be great if we could set tags then to differentiate between the definitions created by this tool, and the ones created by Terraform.

Out specific use case is that we would like to cleanup old task definitions created by ecs-deploy, but not the ones created by Terraform.

[myufa]

Bumping this, it would be very helpful!

[nwsparks]

an alternative to this could be an option to not copy the tags so that ecs deploy resources were created without tags in order to distinguish them.

the code that is doing the copying of tags was added here #139