Changed from OS_PROJECT_ID to OS_PROJECT_NAME.

While `do` looks cleaner, forcing this extra option in ansible.cfg
seems to be more invasive. It would be better to keep the traditional
approach of `set dummy = ` instead.

* Add pre-upgrade task for moving credentials file

This reverts commit 7ef9f4df.

* add python interpreter workaround for localhost

Kubernetes makes this namespace automatically, so there is
no need for kubespray to manage it.

* Added retries in pre-upgrade.yml and retries while applying kube-dns.yml

* Removed trailing spaces

This file should only be updated during kubelet upgrade so that
master components are not accidentally restarted first during
preinstall stage.

Labels from role (node-role.k8s.io/node) and labels from inventory are merged into node-labels parameter in kubelet

Addition of the .creds extension to the credentials files generated by password lookup in order for Ansible not to consider them as inventory files with inventory_ignore_extensions set accordingly (#2446)

As requested

Ensure that kube-apiserver will respond even if one of the nodes are down.