Merge branch '2.1.x' into 2.2.x

Closes gh-22193

Author: wilkinsona

ci/images/get-docker-url.sh

@@ -1,5 +1,5 @@
 #!/bin/bash
 set -e
 
-version="19.03.11"
+version="19.03.12"
 echo "https://download.docker.com/linux/static/stable/x86_64/docker-$version.tgz";