Add latest task definition option to run command

[jamesrwhite]

This adds the --latest-task-definition flag to the run command, the goal is to have it function identically to how it does for the deploy command.

We needed this to support our application deployment flow of:

1. Registering a new task definition:
   $ ecspresso register
2. Running database migrations using the newly registered task definition:
   $ ecspresso run --latest-task-definition --overrides '{...}'
3. Deploying and updating our service using the latest definition:
   $ ecspresso deploy --latest-task-definition --update-service

[fujiwara]

Thank you, I've recognized the use case. Great patch!

[fujiwara]

https://github.com/kayac/ecspresso/releases/tag/v1.1.0 released.

[jamesrwhite]

Thanks for dealing with this so quickly! Would you be able to push a new version of the orb to CircleCI also?

[fujiwara]

@jamesrwhite
https://circleci.com/developer/orbs/orb/fujiwara/ecspresso CireleCI orb was updated!

[Songmu]

@jamesrwhite

Very good work!

Interestingly, when I added "--latest-task-definition" before (#161), my motivation was the same as yours that I wanted to run the migration before deployment.

In fact, what you want to do can also be written as follows.

$ ecspresso -conf conf.yml run --overrides '{...}'
$ ecspresso -conf conf.yml deploy --latest-task-definition

In this case, the ecspresso run registers a new task definition and executing the task. Also, the --update-service option has been set to true by default since ecspresso v1, so it is not required.

However, your command declaration is clear and without any implications so, which one is better is a matter of taste, I think.