update consul clusters to use draining

[tfhartmann]

This version of the module puts the requirement on the user of the
module to set instances to DRAINING in some fashion. In our case we are
using our sidecar container, which includes a healthcheck which set the
DRAINING State.

updates the sidecar container used.
This keeps this module inline with
FitnessKeeper/terraform-aws-consul-agents

I suggest we bump the major version of this module, although this PR won't break the module when you run terraform, it will change the assumption on how new tasks get added.

[hakamadare]

i agree with cutting a new major release; if i understand correctly, this is a breaking change, b/c it changes the names of the parameters that the module accepts

[hakamadare]

[tfhartmann]

i agree with cutting a new major release; if i understand correctly, this is a breaking change, b/c it changes the names of the parameters that the module accepts

Yes! Also that! In addition the old version of the module somewhat handled making sure the cluster would survive the instances being cycled under the ASG's by allowing you to span multiple ASG's *and *multiplying the desired task count by two, in this version the desired count is the correct count, so if you ask for a count of 3, you'll get three tasks, and we leave it to another facility to set the instances to draining. In this case, we provide all hooks to do this, but the parameter definitions = ["ecs-cluster"] still needs to be set. Actually in typing that, I'm going to change the default value of definitions to the above, so that some trying out the module with the default settings will get a sense of how that all works.