DRY up Subprocess.spawn

This was recommended by RuboCop as a means of reducing the number of
statements in the method. I'm not really convinced this was worth it,
but it's an experiment for now.

Change-Id: I88b8e7adb5539650fe490b889f2809fff1d57146
Reviewed-on: http://gerrit.causes.com/44894
Tested-by: jenkins <jenkins@brigade.com>
Reviewed-by: Shane da Silva <shane.dasilva@brigade.com>
Disable MultilineOperationIndentation cop

This doesn't appear to be useful for this project.

Change-Id: I9aad5fd1bbbc10748a141462f9b074e16cf1c01d
Reviewed-on: http://gerrit.causes.com/44895
Tested-by: jenkins <jenkins@brigade.com>
Reviewed-by: Shane da Silva <shane.dasilva@brigade.com>