[ANNOUNCE] DataSketches C++/Python 3.4.0 released!

[Jon Malkin <jm...@apache.org>]

Hello all,

We are pleased to announce the release of DataSketches C++/Python 3.4.0.
This component provides a header-only C++ library, and also includes a thin
wrapper to enable sketches within python.

Summary of changes in this version:

   - addition of Quantiles sketch: the algorithm is largely obsolete vs KLL
   but this provides compatibility for existing sketches
   - support for serde instances in all relevant sketches; class-level
   templates are now marked deprecated
   - greater API consistency across quantiles, KLL, and REQ
      - all three support a new public get_sorted_view() interface
      - all three support rank and quantile queries with an optional
      inclusive mode
   - cmake minimum version bump to 3.16
   - Kolmogorov-Smirnov test for KLL and classic Quantiles, also available
   in python
   - code cleanup and bugfixes


Download site: https://datasketches.apache.org/docs/Community/Downloads.html

Release tag, with link to source and repository:
https://github.com/apache/datasketches-cpp/releases/tag/3.4.0

Build and installation instructions:
https://github.com/apache/datasketches-cpp/tree/3.4.0

Pypi info for Python convenience binaries:
https://pypi.org/project/datasketches/

Thank you to the PMC and everyone who reviewed and voted on this release.

  jon