Multi-operating system considerations

Looking at each of the core Ansible modules used in the three roles, stack-install, stack-config, and wordpress, we are using a few that will not work on our newly introduced Ubuntu box. Let's quickly work through each one and see what we need to take into account when targeting two very different operating systems:

• yum: The yum module is the package manager used for Red Hat-based machines such as CentOS, as Ubuntu is based on Debian, which uses apt. We will need to break out the parts of our playbook that uses the yum module to use the apt module instead.
• yum_repository: As mentioned, we will need to use an apt equivalent module, which is apt_repository.
• user: The user module works pretty much the same on both operating systems, as we are not giving our user escalated privileges. There aren't any special considerations we need to make, other than double-checking the correct group is available.
• template, file, copy, and lineinfile: All four of these modules...