Remove query method from client.py

[martinmr]

Other clients do not have the query as part of the client interface,
only the transaction interface can do that. This change removes query
from the client interface so that it matches the rest of the clients.

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This change is 

[danielmai]

Made a couple of comments about docstrings. Otherwise, looks good. This will be a breaking API change where users need to run Txn#query (which can be read_only or best_effort) instead of DgraphClient#query.

Reviewed 5 of 5 files at r1.
Reviewable status: all files reviewed, 2 unresolved discussions (waiting on @martinmr)

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tests/test_essentials.py, line 32 at r1 (raw file):

        """Tests what happens when making a mutation on a txn after querying
        on the client."""

This docstring should be updated. The query's no longer done on the "client", which I presume means the DgraphClient object.

I'm glad this change makes the number of txns explicit.

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tests/test_txn.py, line 239 at r1 (raw file):

        query = '{ me() {} }'

        # Using client.query helper method

Remove comment.

[martinmr]

Reviewable status: 3 of 5 files reviewed, 2 unresolved discussions (waiting on @danielmai)

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tests/test_essentials.py, line 32 at r1 (raw file):

Previously, danielmai (Daniel Mai) wrote…

        """Tests what happens when making a mutation on a txn after querying
        on the client."""

This docstring should be updated. The query's no longer done on the "client", which I presume means the DgraphClient object.

I'm glad this change makes the number of txns explicit.

Done.

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tests/test_txn.py, line 239 at r1 (raw file):

Previously, danielmai (Daniel Mai) wrote…

Remove comment.

Done.