DANGEROUS: delete-user-namespaces should not be activated by default on unistall!!!

[rafaeltuelho]

Description

unless you explicitly specify the keep_namespaces=true extra-var the uninstall playbook includes by default the delete-user-namespaces role which wipes all user namespaces in the cluster.

Expected Behavior

In my opinion, this should not be the default behavior for uninstall. Consider tha fact that integr8tly can be provisioned on top of a general proprose Openshift cluster shared by users running different projects.

Actual Behavior

All non system-admin created namespaces/project will be wiped by the uninstall playbook.

Environment

• Operating system: RHEL 7.6
• OpenShift version: 3.11.104

oc v3.11.104
kubernetes v1.11.0+d4cacc0
features: Basic-Auth GSSAPI Kerberos SPNEGO

Server 
openshift v3.11.104
kubernetes v1.11.0+d4cacc0

• Ansible version:

ansible 2.6.18
  config file = /root/integr8tly/installation/ansible.cfg
  configured module search path = [u'/root/integr8tly/installation/library']
  ansible python module location = /usr/lib/python2.7/site-packages/ansible
  executable location = /bin/ansible
  python version = 2.7.5 (default, Jun 11 2019, 12:19:05) [GCC 4.8.5 20150623 (Red Hat 4.8.5-36)]

• Project Version/Tag: release-1.5.0

Steps to reproduce

1. run the uninstall playbook without setting the keep_namespaces variable.