* Fix Failure talking to yum: Cannot find a valid baseurl for repo: base/7/x86_64 if Install packages in CentOS using proxy
* Add proxy to /etc/yum.conf if http_proxy is defined
* Changre raw execution to use yum module
Changed raw exection to use yum module provided by Ansible.
* Replace ansible_ssh_* by ansible_*
Ansible 2.0 has deprecated the “ssh” from ansible_ssh_user, ansible_ssh_host, and ansible_ssh_port to become ansible_user, ansible_host, and ansible_port. If you are using a version of Ansible prior to 2.0, you should continue using the older style variables (ansible_ssh_*). These shorter variables are ignored, without warning, in older versions of Ansible.
I am not sure about the broader impact of this change. But I have seen on the requirements the version required is ansible>=2.4.0.
http://docs.ansible.com/ansible/latest/intro_inventory.html
Migrate older inline= syntax to pure yml syntax for module args as to be consistant with most of the rest of the tasks
Cleanup some spacing in various files
Rename some files named yaml to yml for consistancy
