Dynamic Path support

New feature

• Validation failures now tell what path was traversed in the schema, until the validation error was found, in the ValidationFailure.dynamicPath property.

Other improvements and bugfixes

• fix signature of FormatValidator interface to return FormatValidationFailure instead of ValidationFailure (this might be a very minor BC-break)
• parser improvements:
  • not accepting malformed json with missing commas in array elements - bugfix contributed by @soumyajit-sahu , congrats!
  • throwing exception on duplicate keys
• dependency upgrades (only patch versions)