Remove `needs/privileged` from postgresql test. (#19907)

* Remove `needs/privileged` from postgresql test.
* Add python 3 support to postgresql tests.

test/integration/targets/postgresql/aliases

@@ -1,5 +1,4 @@
 destructive
-needs/privileged
 posix/ci/group1
 postgresql_db
 postgresql_privs

test/integration/targets/setup_postgresql_db/tasks/main.yml

@@ -1,10 +1,20 @@
+- name: python 2
+  set_fact:
+    python_suffix: ""
+  when: ansible_python_version | version_compare('3', '<')
+
+- name: python 3
+  set_fact:
+    python_suffix: "-py3"
+  when: ansible_python_version | version_compare('3', '>=')
+
 - include_vars: '{{ item }}'
   with_first_found:
     - files:
-        - '{{ ansible_distribution }}-{{ ansible_distribution_major_version }}.yml'
-        - '{{ ansible_distribution }}-{{ ansible_distribution_version }}.yml'
-        - '{{ ansible_os_family }}.yml'
-        - 'default.yml'
+        - '{{ ansible_distribution }}-{{ ansible_distribution_major_version }}{{ python_suffix }}.yml'
+        - '{{ ansible_distribution }}-{{ ansible_distribution_version }}{{ python_suffix }}.yml'
+        - '{{ ansible_os_family }}{{ python_suffix }}.yml'
+        - 'default{{ python_suffix }}.yml'
       paths: '../vars'
 
 # Make sure we start fresh

test/integration/targets/setup_postgresql_db/vars/Ubuntu-16-py3.yml

@@ -0,0 +1,10 @@
+postgresql_service: "postgresql"
+
+postgresql_packages:
+  - "postgresql"
+  - "postgresql-common"
+  - "python3-psycopg2"
+
+pg_hba_location: "/etc/postgresql/9.5/main/pg_hba.conf"
+pg_dir: "/var/lib/postgresql/9.5/main"
+pg_ver: 9.5