Move to Ansible 3.4.0 (#7672)

* Ansible: move to Ansible 3.4.0 which uses ansible-base 2.10.10

* Docs: add a note about ansible upgrade post 2.9.x

* CI: ensure ansible is removed before ansible 3.x is installed to avoid pip failures

* Ansible: use newer ansible-lint

* Fix ansible-lint 5.0.11 found issues

* syntax issues
* risky-file-permissions
* var-naming
* role-name
* molecule tests

* Mitogen: use 0.3.0rc1 which adds support for ansible 2.10+

* Pin ansible-base to 2.10.11 to get package fix on RHEL8

roles/download/tasks/prep_download.yml

@@ -38,7 +38,7 @@
   run_once: true
   register: test_become
   changed_when: false
-  ignore_errors: true
+  ignore_errors: true  # noqa ignore-errors
   become: true
   when:
     - download_localhost
@@ -53,7 +53,7 @@
   run_once: true
   register: test_docker
   changed_when: false
-  ignore_errors: true
+  ignore_errors: true  # noqa ignore-errors
   become: false
   when:
     - download_localhost