allow slurm to create a cluster if it doesn't exit, and not fail if it does

roles/slurm-start/tasks/main.yml

@@ -48,6 +48,7 @@
 - name: "create cluster in slurm db"
   shell:  "{{slurm_dir}}/bin/sacctmgr -i create cluster {{ clustername }}"
   sudo: true
+  ignore_errors: true
 
 - name: start slurmctl
   service: name=slurmctld state=started enabled=yes