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

tests/testcases/015_check-nodes-ready.yml

@@ -12,7 +12,7 @@
       bin_dir: "/usr/local/bin"
     when: not ansible_os_family in ["Flatcar Container Linux by Kinvolk"]
 
-  - import_role:
+  - import_role:  # noqa unnamed-task
       name: cluster-dump
 
   - name: Check kubectl output
@@ -21,7 +21,7 @@
     register: get_nodes
     no_log: true
 
-  - debug:
+  - debug:  # noqa unnamed-task
       msg: "{{ get_nodes.stdout.split('\n') }}"
 
   - name: Check that all nodes are running and ready