Bump up Ansible to 4.x

As per [1] and [2] - Ansible versions prior to 4 are not maintained.

[1]: https://docs.ansible.com/ansible/devel/reference_appendices/release_and_maintenance.html#ansible-community-package-release-cycle
[2]: https://docs.ansible.com/ansible/devel/reference_appendices/release_and_maintenance.html#ansible-core-release-cycle

Change-Id: I06cf6723361010e0a7c6eb07f2d9e570192cd9a4

releasenotes/notes/ansible-4-1e08eb3acd1768fe.yaml

@@ -0,0 +1,4 @@
+---
+features:
+  - |
+    Ansible 4 is now supported and used by default.

scripts/env-setup.sh

@@ -6,7 +6,7 @@ set -euo pipefail
 # NOTE(pas-ha) the above exports some useful variables like
 # $PYTHON , $PIP and $VENV depending on venv install or not
 
-DEFAULT_PIP_ANSIBLE='>=2.9,<2.11'
+DEFAULT_PIP_ANSIBLE='>=4,<5'
 
 ANSIBLE_COLLECTIONS_REQ=${ANSIBLE_COLLECTIONS_REQ:-$(dirname $0)/../ansible-collections-requirements.yml}
 ANSIBLE_COLLECTION_SOURCE_PATH=
@@ -25,6 +25,7 @@ ANSIBLE=${VENV}/bin/ansible
 if [ -f "$ANSIBLE" ]; then
   ${PIP} uninstall -y ansible
   ${PIP} uninstall -y ansible-base
+  ${PIP} uninstall -y ansible-core
 fi
 ${PIP} install "${ANSIBLE_SOURCE_PATH}"
 

tox.ini

@@ -86,7 +86,7 @@ deps =
 usedevelop = False
 allowlist_externals = bash
 deps =
-  ansible>=2.10.0,<2.11
+  ansible>=4,<5
   ansible-lint>=4.3.0,<5
 commands =
     bash tools/ansible-lint.sh