The _get_records function currently returns the first 100 records. As our TXT is added most recently, if you have > 100 records it will not be returned.
I've changed the function to sort by ID DESC, so it will always return the latest 100 records.
Even though DNSimple is technically covered with lexicon not all
systems can install python pip's easily. For these systems it is useful
to have pure shell script API interactions.