nchristensen authored 2 years ago and Andreas Klöckner committed 2 years ago

Needs a version that includes the `Self` type.

`__init__.py` uses PEP 526 variable annotations, which are supported only in 3.6+

Since commit d855850c, function `six.moves.intern` is used in pytools,
but this function appeared only in six 1.8.0.
This commit prevents an error while importing pytools with an older six installed.