Merge "Move precheck into its own role"

ansible/prechecks.yml

----
-- hosts: all
-  roles:
-    - prechecks

ansible/roles/aodh/tasks/precheck.yml

+---

ansible/roles/barbican/tasks/precheck.yml

+---

ansible/roles/baremetal/tasks/precheck.yml

+---

ansible/roles/bifrost/tasks/precheck.yml

+---

ansible/roles/ceilometer/tasks/precheck.yml

+---

ansible/roles/ceph/tasks/precheck.yml

+---

ansible/roles/certificates/tasks/precheck.yml

+---

ansible/roles/cinder/tasks/precheck.yml

+---

ansible/roles/cloudkitty/tasks/precheck.yml

+---

ansible/roles/collectd/tasks/precheck.yml

+---

ansible/roles/common/tasks/precheck.yml

+---

ansible/roles/congress/tasks/precheck.yml

+---

ansible/roles/destroy/tasks/precheck.yml

+---

ansible/roles/elasticsearch/tasks/precheck.yml

+---

ansible/roles/etcd/tasks/precheck.yml

+---

ansible/roles/glance/tasks/precheck.yml

+---

ansible/roles/gnocchi/tasks/precheck.yml

+---

ansible/roles/grafana/tasks/precheck.yml

+---

ansible/roles/haproxy/tasks/precheck.yml

+---