Require additonal properties to be set in ResourceTypeSchema

[MattMCloudy]

Issue #, if available: #33

Description of changes: This commit adds additionalProperties as a required field inside of the provider.definition.schema.v1.json meta-schema. This will allow the checks here to be enforced when additionalProperties is not defined. As it is now, the properties can be added to instances of the schema which are not tracked inside of the registered schema.

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[rjlohan]

This only prevents at the top level. However additionalProperties is a valid entity all the way down the tree wherever a schema declares "type": "object"

This is really the hard bit. It means schema authors have to add "additionalProperties": "false" throughout their schema. Would prefer to think up a smarter way to address this problem.

[MattMCloudy]

This only prevents at the top level. However additionalProperties is a valid entity all the way down the tree wherever a schema declares "type": "object"

This is really the hard bit. It means schema authors have to add "additionalProperties": "false" throughout their schema. Would prefer to think up a smarter way to address this problem.

I agree, it would be much better if there was a way to have everit make "additionalProperties": "false" be the default behavior.

[rjlohan]

For the purpose of closing this on the side of enforcing the contract, let's add the restriction through the schema tree. We can work out a smarter way to achieve same later. I'd rather this then having to break a resource provider later.

[MattMCloudy]

I'll run pre-commit and post a new revision with the changes.