Drop Docker, it's not required when using docker-machine with an external driver

tasks/install-docker-machine.yml

@@ -2,7 +2,7 @@
 
 - name: Get Docker Machine
   get_url:
-    url: "https://github.com/docker/machine/releases/download/{{ docker_machine_version }}/docker-machine-{{ ansible_system }}-{{ ansible_architecture }}"
+    url: "https://github.com/docker/machine/releases/download/{{ docker_machine_version | default('v0.15.0') }}/docker-machine-{{ ansible_system }}-{{ ansible_architecture }}"
     dest: /tmp/docker-machine
 
 - name: Install Docker Machine

tasks/install-docker.yml

----
-- name: Add Docker signing key
-  apt_key:
-    url: https://download.docker.com/linux/debian/gpg
-    state: present
-
-- name: Add Docker repo
-  apt_repository:
-    repo: 'deb [arch=amd64] https://download.docker.com/linux/debian {{ ansible_distribution_release }} stable'
-    state: present
-    filename: 'docker'
-
-- name: Install Docker
-  apt:
-    pkg: docker-ce
-    update_cache: true

tasks/install-redhat.yml

----
-
-- name: RHEL | Install GitLab GPG key
-  rpm_key:
-    state: present
-    key: https://packages.gitlab.com/gpg.key
-  when: ansible_os_family == 'RedHat'
-  tags:
-    - gitlab
-    - gitlab-gpg
-
-- name: Install GitLab Runner dependencies
-  yum:
-    name: '{{ item }}'
-    state: present
-  with_items:
-    - pygpgme
-    - yum-utils
-
-- name: Add GitLab Runner rpm repo
-  template:
-    src: "runner.repo.j2"
-    dest: "/etc/yum.repos.d/runner_{{ gitlab_runner_package_name }}.repo"
-
-- name: Install GitLab Runner
-  yum:
-    name: "{{ gitlab_runner_package_name }}"
-    state: latest
-    update_cache: yes

tasks/main.yml

 ---
-- name: Install GitLab Runner (Debian)
-  import_tasks: install-debian.yml
-  when: ansible_os_family == 'Debian'
-
-- name: Install GitLab Runner (RedHat)
-  import_tasks: install-redhat.yml
-  when: ansible_os_family == 'RedHat'
-
-- name: Install Docker
-  import_tasks: install-docker.yml
+- name: Install GitLab Runner
+  import_tasks: install-runner.yml
 
 - name: Install Docker Machine
   import_tasks: install-docker-machine.yml