Fix integration test error on ansible devel branch

- Remove centos6 platforms for integration tests on
  the ansible devel branch from the azure-pipelines.
- Add delegate_to to each task of integration test for
  synchronized module on devel branch
- Modify invalid parameter test to use key instead of name
  for sysctl module
- Replace lookup plugin to slurp module in integration tests
  for selinux module
- Add creating working directory task in integration tests
  for acl module

Signed-off-by: Hideki Saito <saito@fgrep.org>

tests/integration/targets/acl/tasks/acl.yml

@@ -23,6 +23,16 @@
   group:
     name: "{{ test_group }}"
 
+- name: Clean up working directory and files
+  file:
+    path: "{{ output_dir }}"
+    state: absent
+
+- name: Create working directory
+  file:
+    path: "{{ output_dir }}"
+    state: directory
+
 - name: Create ansible file
   file:
     path: "{{ test_file }}"