add checksum creator for isos (neil)

1 job for devel in 31 seconds (queued for 8 seconds)
Status Name Job ID Coverage
  Test
failed shellcheck #115
container

00:00:31

 
Name Stage Failure
failed
shellcheck Test There has been a runner system failure, please try again
Did you mean: 
| sudo tee -a isos/"${arch}"/CHECKSUM;

For more information:
https://www.shellcheck.net/wiki/SC1001 -- This \/ will be a regular '/' in ...
https://www.shellcheck.net/wiki/SC2086 -- Double quote to prevent globbing ...
Cleaning up file based variables
Running cleanup_file_variables in runner helper
ERROR: Job failed (system failure): exit status 2