A pull option for run to allow multiple services to be pulled

[lox]

This adds a top-level pull property that is used with run to indicate you want to pull down multiple services. If any of them are prebuilt in a previous step, they will be pulled down.

steps:
  - name: ":docker: Build"
    plugins:
      docker-compose#master:
        build: 
          - app
          - app_dependency
        image-repository: index.docker.io/org/repo

  - wait

  - name: ":docker: Test"
    plugins:
      docker-compose#master:
        run: app
        pull: 
          - app_dependency

This will probably merit a bump to 2.0.0.

Closes #96 and #86.

[grrowl]

Tested (as docker-compose#add-pull-option on a v3.0-beta.39 agent) with one service under pull:. Works a charm, running a docker-compose ... pull <service> command and displaying the output (and the exit code)

[lox]

Really appreciate that @grrowl!

[grrowl]

Hi, are we cutting a new release for docker-compose-buildkite-plugin@1.8.5 with this code included? Our pipeline references plugins: docker-compose#add-pull-option, and deleting the branch here halted our pipeline :\

[lox]

I didn't even think of that, sorry @grrowl!!! I've restored the branch.

We will cut a 2.0.0 release likely, as there have been some other changes in master that merit it.

[chriwu]

Awesome work - thank you Buildkite! 😍 🎉

[toolmantim]

v2.0.0 is now out, and the readme’s been updated too 🎉