Add more detailed steps for deployment

[dhinus]

I'm not sure that this covers all possible edge cases, but it should cover the common use case where you want to test a PR after another one has been merged by someone else and your branch is stale. Please let me know if you think that something is missing.

I also moved "point the web proxy at the new cluster" to the "Fresh deploy" section, because I don't think it's required when doing a standard deploy.

[vivian-rook]

I modified the instructions slightly to reference that github can update as well. Not sure if it is worth noting that if all is configured correctly github should block merges on stale branches.

[dhinus]

Not sure if it is worth noting that if all is configured correctly github should block merges on stale branches.

Yeah I think it's worth noting it.

My main concern was to prevent deploying stale branches without noticing, I think that is still possible if you don't notice the "conflict" warning in Github and proceed to run "deploy.sh"?

[vivian-rook]

My main concern was to prevent deploying stale branches without noticing, I think that is still possible if you don't notice the "conflict" warning in Github and proceed to run "deploy.sh"?

This is correct. Github can't stop you from deploying, only merging. If we wanted to be really paranoid we could maybe update deploy.sh to check if the branch is stale. Though I'm not sure it is worth the extra complexity.