Output JSON for `--json` switch in CLI tool

for create, deploy, and undeploy subcommands.
Merge pull request #157 from spotify/dano/cli-hosts-explicit-helios-version

cli: hosts: explicit helios version column
Merge pull request #156 from spotify/dxia/more-json-output

Output JSON for `--json` switch in CLI tool
Output valid JSON for multi-domain CLI commands