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

mitogen.yml

@@ -5,7 +5,7 @@
 - hosts: localhost
   strategy: linear
   vars:
-    mitogen_version: 0.2.9
+    mitogen_version: 0.3.0rc1
     mitogen_url: https://github.com/dw/mitogen/archive/v{{ mitogen_version }}.tar.gz
     ansible_connection: local
   tasks:
@@ -13,6 +13,7 @@
       file:
         path: "{{ item }}"
         state: directory
+        mode: 0755
       become: false
       loop:
         - "{{ playbook_dir }}/plugins/mitogen"
@@ -40,3 +41,4 @@
         section: defaults
         option: strategy
         value: mitogen_linear
+        mode: 0644