Convert repository to Ansible Collection format

[bartowl]

This PR fixes #58 and makes it possible to use this code as ansible collection opitzconsulting.ansible-oracle.
For upstream PR to oravirt the top level galaxy.yml should be updated to point to different namespace (oravirt?).

Please note, that at least at this stage it is not intended to upload this collection to galaxy repository and please do not upload it. If it will be done, then it should be done from the main git repository (oravirt) and not from any fork.

Here is a simple example how to download this collection:

[user@host ~]$ mkdir coll
[user@host ~]$ ANSIBLE_COLLECTIONS_PATH="$(pwd)/coll" ~/.local/bin/ansible-galaxy collection install -v -r requirements.yml -p coll
Using /etc/ansible/ansible.cfg as config file
Starting galaxy collection install process
Process install dependency map
Starting collection install process
Installing 'opitzconsulting.ansible-oracle:2.0.0' to '/home/user/coll/ansible_collections/opitzconsulting/ansible-oracle'
Created collection for opitzconsulting.ansible-oracle at /home/user/coll/ansible_collections/opitzconsulting/ansible-oracle
opitzconsulting.ansible-oracle (2.0.0) was installed successfully
[user@host ~]$ cat requirements.yml
collections:
  - name: https://github.com/bartowl/ansible-oracle.git
    type: git
    version: add_collection # (git branch or tag name here)

Usage in playbooks is then typical to any other ansible collections - you have either to prefix the role names with opitzonsulting.ansible-oracle or use:

collections:
  - opitzconsulting.ansible-oracle

on the play level