Create ansible collection

This effort was undertaken following a discussion on #100 (closed), and restructures the ansible directory into the Galaxy collection structure. This will allow us to publish the collection to Galaxy at some point in the future. In the meantime, users would need to install the collection via git URL. Before we can publish the collection to Galaxy, we need to release the content under an open-source license, per the galaxy.yml schema notes for the license attribute.

The infrastructure team hopes to use the latter method to continue testing for using Ansible to configure gitlab.com, by setting GET as an upstream dependency and extending where necessary for .com-specific settings, depending on timing for when this functionality is able to meet acceptance criteria and merged for the next release of GET.