check why remote references don't work

[hauner]

Originally posted by @rachel-singh in #69

[hauner]

tried with this simple example: https://raw.githubusercontent.com/openapi-processor/openapi-processor-core/master/src/testInt/resources/tests/ref-into-another-file/inputs/openapi.yaml and it works with both parsers.

[hauner]

To everyone: if you have an example that fails, please let me know so I can reproduce the issue.