Ensure additionalProperty uses correct schema.

[fiasco]

I encountered this issue when attempting to validate data against this schema:

EnvironmentFlags:
      type: object
      description: An array of various flags that indicate functionality associated with the environment.
      additionalProperties:
        type: object
        properties:
          cde:
            type: boolean
            description: Determines if the environment is on-demand.

The Properties::validate() method currently attempts to validate additionalProperties by their parent definition which results in an error which validating valid data.

[fiasco]

I've added a unit test for this scenario and updated the PR to support both existing and new scenarios.

[scaytrase]

I'm not sure I'm getting this correct. I see incorrect match for spec and test data in your UT.

if you have additional properties being specd by object: props: flag: bool than your test data should look like

$data = ['someUnknownProperty' => ['flag' => true]];

For current format flag should be known property of main object, not for additionalProperties