delete unused tiny models
```
                           [ok] bart-tiny-random/
                           [ok] tiny-marian-en-de/
                           [ok] tiny-mbart/
                           [deleted] distilbert_tiny_random/
                           [ok] tiny-ctrl/
                           PRE tiny-dbmdz-bert-large-cased-finetuned-conll03-english/
                           [ok] tiny-distilbert-base-cased-distilled-squad/
                           [ok] tiny-distilbert-base-cased/
                           [ok] tiny-distilbert-base-uncased-finetuned-sst-2-english/
                           [ok] tiny-distilroberta-base/
                           [ok] tiny-gpt2/
                           [ok] tiny-xlnet-base-cased/
```
and make sure the ones that remain are usable/have tokenizer files.
This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.
