Chris/fix build create

[perigrin]

This brings in various fixes that were necessary to bring for the most recent JPC Build.

• UUIDs were removed from Admin and BuildCreate request structs
• Empty POST bodies are allowed (we were accidentally sending an empty string on POST before)
• removed any comments about short UUIDs (minimally closes PR #87)
• various small tweaks and fixes to bring subcommands into alignment with expectations set (i.e. docker builds rs for racks)