Feature Request: Add version of manifest format to the codius manifest

[traviscrist]

Add support for manifest versions in codius-manifest which will be where all manifest version logic lives. Codiusd and codius will use the codius-manifest npm module for verification of version and for generation of manifests.

• New optional field added to codius manifest called manifestVersion
• manifestVersion field uses format of YYYY-MM-DD` where YYYY is the year, MM is the month, and DD is the current day.
• Codius Manifest versions will be stored in json schema files with an individual file used for each version.
• Manifest Validation (codiusd & codius)
  • A function will be exposed to codiusd & codius which allows the validation of a manifest.
  • This function will only validate the manifest based on the version and if errors our found return informative errors on why validation failed.
  • If no manifestVersion is present the validation will be performed against the oldest version in codius-manifest module.
  • If the manifestVersion is present validation will be performed against that exact version. If that version is not found an error will be returned with information about which versions are valid.
• Codius Manifest Generation (codius)
  • During the codius cli generation of a manifest if no version if provided it will use the latest and add that version to the generated manifest.
  • manifestVersion will be a supported field for the codius.json file in the codius cli
  • If manifestVersion is set in the codius.json file then only that version of the manifest will be used for validation and manifest generation.