Module: Tower inventory source module (#37110)

* tower_inventory_source: Add support for the inventory source via ansible-tower-cli.

* Add test coverage for tower_inventory_source.

* Update version_added to 2.7

test/integration/targets/tower_inventory_source/aliases

@@ -0,0 +1,2 @@
+cloud/tower
+posix/ci/cloud/group4/tower

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

@@ -0,0 +1,34 @@
+---
+- name: Add a Tower credential
+  tower_credential:
+    description: Credentials for Openstack Test project
+    name: openstack-test-credential
+    kind: openstack
+    organization: Default
+    project: Test
+    username: admin
+    host: https://example.org:5000
+    password: passw0rd
+    domain: test
+
+- name: Add a Tower inventory
+  tower_inventory:
+    description: Test inventory
+    name: openstack-test-inventory
+    organization: Default
+
+- name: Create a source inventory
+  tower_inventory_source:
+    name: source-test-inventory
+    description: Source for Test inventory
+    inventory: openstack-test-inventory
+    credential: openstack-test-credential
+    overwrite: True
+    update_on_launch: True
+    source_vars: "---\nprivate: false"
+    source: openstack
+  register: result
+
+- assert:
+    that:
+      - "result is changed"