Automated cherry pick of #8813 release 3.1#8902

Merged

gyuho merged 2 commits intoetcd-io:release-3.1from jpbetz:automated-cherry-pick-of-#8813-release-3.1

Nov 22, 2017

+566-215

Commits on Nov 21, 2017

vendor: Switch from boltdb v1.3.0 to coreos/bbolt v1.3.1-coreos.3
jpbetz
committed
test: Clean agent directories on disk before functional test runs, not after
jpbetz
committed