Running tests produces lots of output

I just setup a new dev environment for papermill with conda create ... and then pip install -r requirements-dev.txt and executed pytest in the top level directory of the repository.

The tests pass but I end up with several screens full of:

/Users/username/miniconda/envs/papermill/lib/python3.6/importlib/_bootstrap.py:219: ImportWarning: can't resolve package from __spec__ or __package__, falling back on __name__ and __path__
  return f(*args, **kwds)

and other warnings that come from papermill itself like:

/Users/username/git/nteract/papermill/papermill/iorw.py:46: UserWarning: The specified input file (/Users/username/git/nteract/papermill/papermill/tests/parameters/example.yaml) does not end in '.ipynb' or '.json'
  "The specified input file ({}) does not end in '.ipynb' or '.json'".format(path)

Does anyone know what causes the first kind of error/console output? I'd like to work on removing/reducing it. Lots of noisy output from our tests that is "known to be harmless" trains us in ignoring the output (at least it trains me to do that). The warnings from inside papermill are probably easier to track down/capture.