Update HISTORY.md for 0.7.1/dev
# In progress
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+# TileDB-Py 0.7.1 Release Notes
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## Improvements
* Added support for `df[]` indexing via `tiledb.Array.query` [#411](https://github.com/TileDB-Inc/TileDB-Py/pull/411)
* Modified `stats_dump` to return internal stats as string, allowing for output in Jupyter notebooks [#403](https://github.com/TileDB-Inc/TileDB-Py/pull/403)
