Excess properties in invalid ValidationResult

[djdirtycake]

Hello.
Don't know if it's intended or not, but invalid validation result contains all the properties on the same level, not only missing ones.

Here's an example (both 0.5.0 release and latest commit 2f0facb):

validate(["price": 34.99, "name": "test"], schema: ["required": ["price", "name", "id"]])
▿ ValidationResult
▿ invalid : 1 element
- 0 : "Required properties are missing '["price", "name", "id"]'"

[kylef]

That looks like a bug, thank you for reporting it. c065b6e incorporates a fix for this error.