Merge branch 'master' of https://github.com/kubernetes-incubator/kubespray into etcd-fix-4

.gitignore

.gitlab-ci.yml

README.md

Vagrantfile

ansible.cfg

cluster.yml

contrib/terraform/aws/README.md

contrib/terraform/group_vars

contrib/terraform/openstack/README.md

contrib/terraform/openstack/kubespray.tf

contrib/terraform/openstack/modules/compute/main.tf

contrib/terraform/openstack/modules/compute/variables.tf

contrib/terraform/openstack/variables.tf

docs/calico.md

docs/img/kubernetes-logo.png

docs/netcheck.md

docs/opensuse.md

extra_playbooks/build-cephfs-provisioner.yml

inventory/sample/group_vars/k8s-cluster.yml

inventory/sample/hosts.ini