AWS job configuration - retain comments when written out
It can be useful to include comments in AWS job configuration files to describe the branch of a model or code that is being used. For example, in addition to "modelGitUrl" and "modelSha", a custom "comment-model" field can be used to describe the model being run and/or the purpose of the run. In the past, these comments, which are not used by any code, were output in nshmp-haz-job-config.json and echoed in logs (on screen and in log files). It is useful to retain these arbitrary comment fields in the output, even if they are out of order.