Add info.status

[Dr. Simon Harrer]

Add the status field to the info block:

dataContractSpecification: 0.9.2
id: my-id
info:
  title: My Data Contract
  version: 0.0.1
  status: in development

Possible status values: proposed, in development, active, retired

[Simon AUGER]

It would be useful for my use cases 👍

[Dr. Simon Harrer]

I've added info.status with the possible values "proposed", "in development", "active", and "retired".