Python 3.6 in stretch

[Galbo Branbert <bluenotepads@gmail.com>]

I couldn't find any official statement if Python 3.6 will be the default interpreter in stretch (as it was the current stable when the soft freeze happened it should be, right?)

Some reasons for it: (https://docs.python.org/3/whatsnew/3.6.html)

-)SHA-3, formatted string literals, file system path protocol

-)secrets module has been added to simplify the generation of cryptographically strong pseudo-random number

-)Dicts need 20-25% less memory (kinda a huge deal)