New service management module.

There is a new service management module placed in the pluginsfolder:

  plugins/modules/ipaservice.py

The service module allows to ensure presence and absence of services, and
manage members and certificates of the service.

Here is the documentation for the module:

  README-service.md

New example playbooks have been added:

    playbooks/service/service-host-is-absent.yml
    playbooks/service/service-host-is-present.yml
    playbooks/service/service-is-absent.yml
    playbooks/service/service-is-disabled.yml
    playbooks/service/service-is-present-with-all-attributes.yml
    playbooks/service/service-is-present-without-host-object.yml
    playbooks/service/service-is-present.yml
    playbooks/service/service-member-allow_create_keytab-absent.yml
    playbooks/service/service-member-allow_create_keytab-present.yml
    playbooks/service/service-member-allow_retrieve_keytab-absent.yml
    playbooks/service/service-member-allow_retrieve_keytab-present.yml
    playbooks/service/service-member-certificate-absent.yml
    playbooks/service/service-member-certificate-present.yml
    playbooks/service/service-member-principal-absent.yml
    playbooks/service/service-member-principal-present.yml

New tests added for the module:

  tests/service/test-service.yml