Automated cherry pick of #8427 to release 3.1 branch

[jpbetz]

Fixes: #8411

This is pending #8805, which requires approval before we merge any cherrypicks targeting the 3.1 branch. Submitting it now for testing.

[jpbetz]

cc @liggitt @timothysc

[xiang90]

@jpbetz seems like ci does not like 3.1 release.

[gyuho]

Yeah, Semaphore doesn't support per-branch commands.

We might need manually build release-3.1 test image and add .semaphore.sh to release-3.1 branch. I have scripts to do that here #8764. I can add those images and scripts to release-3.1 branch tomorrow.

[gyuho]

Actually, if we are going to use Go 1.8.5 for release-3.1, we already have image.
So just need to add https://github.com/coreos/etcd/blob/release-3.2/.semaphore.sh to release-3.1.

/cc @xiang90

[jpbetz]

Fixing with #8807. After that is merged I'll rebase this.

[xiang90]

this is ready to merge? /cc @jpbetz

[jpbetz]

@xiang90, yes, this is now ready.

[xiang90]

@jpbetz oops... The commit message actually does match our format. No idea why CI does not catch it.

/cc @gyuho

[gyuho]

It does? Did you mean PR title?

Also 3.1 does check commit title https://github.com/coreos/etcd/blob/release-3.1/test#L202.