Add the need for ansible and template broker to the Prerequisites

[rafaeltuelho]

Description

Should advise that the cluster must have the Ansible and Template Service Broker components deployed into the cluster. Otherwise, the installation fails. These components are optional in OCP 3.11.

Expected Behavior

Have the need for service and template broker explicitly added to Table 1. Prerequisites section on Readme.md

Actual Behavior

Installation fails at reboot_template_broker role execution...

fatal: [127.0.0.1]: FAILED! => {"attempts": 200, "changed": true, "cmd": "oc get clusterservicebroker template-service-broker -o yaml > /tmp/template-service-broker.yml", "delta": "0:00:00.310428", "end": "2019-09-20 18:17:21.223125", "failed_when_result": true, "msg": "non-zero return code", "rc": 1, "start": "2019-09-20 18:17:20.912697", "stderr": "error: the server doesn't have a resource type \"clusterservicebroker\"", "stderr_lines": ["error: the server doesn't have a resource type \"clusterservicebroker\""], "stdout": "", "stdout_lines": []}

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 install playbook on top of an OCP without Template Service Broker deployed.