vip-manager version 1.0

Important Changes:
https://github.com/cybertec-postgresql/vip-manager/releases/tag/v1.0

Note: the configuration method has been changed from v1.0
https://github.com/cybertec-postgresql/vip-manager#migrating-configuration-from-releases-before-v10

and
Disable the GPG checking of signatures of vip-manager package being installed (for RedHat/CentOS)

fixed:
TASK [Install vip-manager] *****************************************
fatal: [10.128.64.157]: FAILED! => {"changed": false, "msg": "Failed to validate GPG signature for vip-manager-1.0_1-1.x86_64"}

Merge pull request vitabaks#43 from jidckii/feature/didable-vip-manag…

…er-if-run-keepalived

Disable vip-manager if run keepalived

Added compatible with Ubuntu 20.04 LTS

tested with Ubuntu Server 20.04 LTS

Scaling: add new haproxy balancer node.

Add playbook "add_balancer.yml".

See more in README.md file -> "Scaling: add new haproxy balancer node".

keepalived task (added parameters, haproxy_check script).

* added parameters "enable_script_security" and "script_user root" into keepalived.conf;
https://www.keepalived.org/manpage.html

* haproxy_check vrrp script moved into /usr/libexec/keepalived directory;

* Restart the keepalived service only during the initial installation or after modification of the configuration file or haproxy_check script.
Do not restart the service when re-executing this playbook.

Update haproxy.yml

* Install lua and haproxy only if the source files has been downloaded.
Do not attempt to install haproxy packages when you re-run this book.
* Restart the haproxy service only during the initial installation or modification of the configuration file.
Do not restart the service when re-executing this playbook.
* Updated tags.