Upgrade to 1.12.5 (kubernetes-sigs#4066)

More Feature/2.8 backports for 2.8.1 (kubernetes-sigs#3911)

* Move node-cidr-mask-size to ControllerManagerextraArgs (kubernetes-sigs#3845)

* Fix apiServerCertSANs in kubeadm config file (kubernetes-sigs#3839)

* Backport kubernetes-sigs#3908

* Update kubernetes to 1.12.4

Fix ubuntu-contiv test failed (kubernetes-sigs#3808)

netchecker agent status is pending

Fix Bionic networking restart error kubernetes-sigs#3430 (kubernetes-…

…sigs#3431)

bump upgrade tests to v2.5.0 commit (kubernetes-sigs#3087)

Weave limits (kubernetes-sigs#2660)

* Raise limits for weave

* Adjust weave limits

Merge pull request kubernetes-sigs#2084 from riverzhang/devicemapper

Fix can not use devicemapper driver

Merge pull request kubernetes-sigs#1880 from mattymo/node_auth_fixes2

Move cluster roles and system namespace to new role

fix graceful upgrade (kubernetes-sigs#1704)

Fix system namespace creation
Only rotate tokens when necessary

Merge pull request kubernetes-sigs#1585 from mattymo/canal_upgrade

Fix upgrade for canal and apiserver cert