Add integration test for ansible-modules-core #460

Please see https://github.com/ansible/ansible-modules-core/pull/460

This integration test uses the `file` module to set `state=touch` on a hard link. Currently in Ansible, that causes an error. [ansible-modules-core/pull/460](https://github.com/ansible/ansible-modules-core/pull/460) fixes that.

n.b. If there is generally a better way to coordinate PRs for changes that span across submodules of the project, please let me know.