after the 3.7 is out we would had to create a new 3.7/master branch, but I would postpone this step at a later point. 

Why? Because I know that there are some fixes in the queue what we would have to forward port to 3.8 and some of them to 3.6. 

This branching will be a lazy one: we will branch it when we have to, but not earlier.

L.