Release Management policy

[naxxfish]

We should probably have a release management policy.

It could go something like this:

• Each release is given a milestone in GitHub and issues (features) are assigned to a release.
• Issues which are to be deferred to later are reassigned a milestone for a different release.
• Pull requests are assigned to a milestone if they are to be included in a release.
• A release is ready when all of the issues assigned to the milestone are closed.
• After a full integration test, a release is tagged from the master branch

Issue Triage process:

• Issue is initially created with no milestone assigned
• Issue may be assigned a milestone as it is prioritised
• Pull requests refer to the issue - if a pull request is to be accepted, it is assigned the milestone of the release it is to be included in.

Topics or areas of work should be labels rather than milestones.

Wider ranging projects should be projects at the organisational level.