Release notes for PyTables 3.7 series

Changes from 3.7.0 to 3.7.1

Compatibility with Python 3.10, numpy 1.21 and HDF5 1.12.
Support for Python 3.5 has been dropped (840 and 850).
Windows: Significantly faster import tables PR #781. Thanks to Christoph Gohlke.
Internal C-Blosc sources updated to 1.21.1 (931). Note that, starting from C-Blosc 1.19 does not include the Snappy codec sources anymore, so Snappy will be not available if you compile from included sources; other packages (like conda or wheels), may (or may not) include it.
Stop using appveyor and deprecated ci-helpers (closes 827).
Switch to git submodule for the management of vendored c-blosc sources.
CI moved to GitHub Actions (GHA).
Drop Travis-CI.
Improved code formatting and notation consistency (873, 868, 865 thanks to Miroslav Šedivý).
Improve the use of modern Python including pathlib, f-strings (859, 855, 839 and 818 thanks to Miroslav Šedivý).
Several improvements to wheels generation in CI (thanks to Andreas Motl @amotl and Matthias @xmatthias).
Simplified management of version information.
Drop dependency on the deprecated distutils.
Modernize the setup script and add support for PEP517 (907).

Fix pkg-config (setup.py) for Python 3.9 on Debian. Thanks to Marco Sulla PR #792.
Fix ROFileNode fails to return the fileno() (633).
Do not flush read only files (915 thanks to @lrepiton).

Drop the deprecated hdf5Version and File.open_count.
the get_tables_version and get_hdf5_version functions are now deprecated please use the coresponding tables.__version__ and tables.hdf5_version instead.