Add JSON Schema validation

[chris-rock]

Description

It is critical that the inspec exec /path/to/profile returns stable output, since its a API that is consumed in other applications. The current test coverage can be improved.

InSpec and Platform Version

0.28.0

Possible Solutions

Develop a JSON Schema for each operation and validate output against it

[chris-rock]

This should be added, once we update the API with #811

[chris-rock]

It is quite difficult to verify hash values with JSON Schema, see http://stackoverflow.com/questions/22229250/how-to-create-json-schema-for-name-value-structure

We should stick to http://json-schema.org/documentation.html v4. We could use https://github.com/ruby-json-schema/json-schema in our tests

[arlimus]

This would have prevented a mistaken exposure in the --format json I merged, fail 🤕