Python 3.5.7 and 3.4.10 released

Python versions 3.5.7 and 3.4.10 have been released. Both are in
'security fixes only' mode and are source-only releases. This is the final
release in the Python 3.4 series. The 3.4 branch has been retired, 'no
further changes to 3.4 will be accepted, and no new releases will be made.