text: Title: Unexpected keyword arguments with textual entailment
  Body: Following the code sample at https://demo.allennlp.org/textual-entailment, I stumbled across an issue (discussed in #4192 ), but has not been solved:
  ```python
  pip install allennlp==1.0.0 allennlp-models==1.0.0
  from allennlp.predictors.predictor import Predictor
  import allennlp_models.tagging
  
  predictor = Predictor.from_path("https://storage.googleapis.com/allennlp-public-models/snli-roberta-2020-07-29.tar.gz")
  
  predictor.predict(
      premise="Two women are wandering along the shore drinking iced tea.",
      hypothesis="Two women are sitting on a blanket near some rocks talking about politics."
  )
  ```
  And it returns an error:
  ```
  ---------------------------------------------------------------------------
  TypeError                                 Traceback (most recent call last)
  <ipython-input-33-9b5a14a8a794> in <module>()
        1 predictor.predict(
        2     premise="Two women are wandering along the shore drinking iced tea.",
  ----> 3     hypothesis="Two women are sitting on a blanket near some rocks talking about politics."
        4 )
  
  TypeError: predict() got an unexpected keyword argument 'premise'
  ```
  It should just return the values.