Purge old upgrade hooks and unused tasks (#1641)

roles/dnsmasq/tasks/main.yml

roles/dnsmasq/tasks/pre_upgrade.yml

roles/etcd/tasks/install_docker.yml

roles/etcd/tasks/main.yml

roles/etcd/tasks/pre_upgrade.yml

roles/kubernetes/master/tasks/main.yml

roles/kubernetes/master/tasks/post-upgrade.yml

roles/kubernetes/master/tasks/pre-upgrade.yml

roles/kubernetes/preinstall/tasks/gitinfos.yml

roles/kubernetes/preinstall/tasks/main.yml

roles/network_plugin/weave/tasks/main.yml

roles/network_plugin/weave/tasks/pre-upgrade.yml

roles/uploads/defaults/main.yml

roles/uploads/tasks/main.yml

uploads.yml