Make Milestones clear and understandable; use more labels

[dharmit]

Currently, we don't have a process for what really goes into the Milestones. We have a mix of different kinds like Epics, User Stories, Features and Documentation going into a Milestone. For example, milestone 2.3. Ideally, Milestone should be a place that gives a quick summary of what the project's goals are for future releases.

We (@dharmit, @girishramnani & @kadel) propose to follow below practice:

• Only Epics should be added to a Milestone.
• Break the Epics into User Stories.
• A User Story be broken down into Acceptance Criteria.
• Each acceptance criterion should have a corresponding GitHub issue.

This will help anyone interested in odo to take a look at a Milestone and understand the project's immediate and future goals/priorities. Anyone interested in the details can go through Issues and filter using labels.

Label issues to track progress

GitHub indicates a Milestone's progress based on the number of Epics closed. This could lead to a false indicator that the project is moving slowly because even though various Stories and/or Criteria of other Epics are closed, the Epics themselves are open.

To overcome this, we must label User Stories and Criteria with a label matching that of the milestone. For example, we could create simple labels like milestone/2.3, milestone/2.4, etc. indicating the odo release that these Stories and Criteria are targeted for. It then becomes relatively simple to go to the Issues and filter based on labels and figure out how many issues are open/closed.

Thoughts?