Usage of Set instead of unique List

[fluktuid]

In my eyes, the specification of the tags in docker-make.yaml is somewhat confusing.

The List of tags is defined as a list of unique values.
So i think it's more straight-forward if a Set is used.

builds:
- name: Latest Stable
  tags:
  ? 1
  ? 1.1
  ? 1.1.0
  ? 1.1.0-acme

[Gerrit91]

Hi there,

there is little movement on this repository. Changing the existing data structure results into a breaking API and I don't think the benefit of the suggested change is very beneficial. I am eager to accept pull request regarding security and bug fixes but I really want to avoid changing the existing API.