Add grpcio-tools

[SohierDane]

Add a dependency on grpcio-tools so we can recompile proto stubs in real time for kaggle_evaluation. It's a small library (<3 MB) and for my purposes the exact version doesn't much matter so I'm hoping this isn't a controversial addition. We do have alternatives if this addition isn't feasible but they're much more invasive, most likely migrating from gRPC to HTTP.

[rosbo]

Can you add a simple smoke test under the tests forder for the grpcio-tools package for the method you are using to ensure we don't regress:

docker-python/tests/test_pandas.py

Lines 1 to 9 in 8cc47ea

	importunittest
	importpandasaspd
	classTestPandas(unittest.TestCase):
	deftest_read_csv(self):
	data=pd.read_csv("/input/tests/data/train.csv")
	self.assertEqual(100, len(data.index))

[SohierDane]

@rosbo I've added the smoke test. Thanks for the recommendation; it caught that the grpcio-tools installation needed to happen in a different location due to the way protobuf is reinstalled.

[rosbo]

this line is redundat.

Given you are using a tempfile.TemporaryDirectory(), it should delete the directory after the "with" claude exits.

[SohierDane]

Ack. I removed that call and the now-pointless try/finally.