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* 57, 58: Now supports arm64 architecture (Apple M1, Raspberry Pi)
* Moved CI from Travis + multibuild to GitHub Actions + cibuildwheel
* Uses Python 3.11.0a7 readline.c (commit aac29af, 2021-10-13), OK for 3.10, 3.9
* Uses Python 3.8.8 readline.c (commit f9d7c12, 2021-02-16), also OK for 3.7
* Uses Python 2.7.18 readline.c (commit f32bcf8, 2019-11-07)
* Updated to build against readline 8.1 (patch-level 2)