Merge pull request rancher#3045 from dweomer/docker/19.03.15

docker/19.03.15

Merge pull request rancher#3045 from dweomer/docker/19.03.15

docker/19.03.15

Merge pull request rancher#3035 from dweomer/docker/19.03.14

docker/19.03.14

Merge pull request rancher#3015 from dweomer/update-readme-v1.5.6

readme: update for v1.5.6

Bump up user docker 19.03.11

Bump up user docker 19.03.11

Add networking info for collect_rancheros_info.sh

Roll back kernel 4.14.138-rancher

Bump rancher/os-hypervvmtools and rancher/os-openvmtools

Support for flushing cert to initrd only