v8.0.0-beta.0

JTD error objects:

• schemaPath and instancePath are consistent with JSON Type Definition RFC
• added properties keyword and params, message (can be removed with messages: false option) to error objects
  JTD error messages can be translated with ajv-i18n v4.0.0-beta.0
• typescript: discriminated union type for JTD errors for type-safe error handling, errors need to be cast to JTDErrorObject type.

JSON Schema errors:

• dataPath property replaced with instancePath (update in your code!)
• "should" replaced with "must" in the messages
• property name is removed from "propertyName" keyword error message (it is still available in error.params.propertyName).