Install Ansible 2.5 on Debian 9 Stretch or Ubuntu 18.04 from source

Ansible is an open-source automation engine like Chef, Puppet, Salt, CFEngine,
It’s a very useful tool if you manage several servers, more than 50 for example. In this post i will show you how to install Ansible 2.5 on Debian Strech or Ubuntu 18.04 from sources.