* remove some Python 2 code

* also remove unused function

* Cache: reduce sleep time

* Update cache.py

* print warnings fix

* restructure

* add comment about our choice for the timeout

* Make if_positive keep strides of then_ if known.

The previous version of `if_positive` always returns a C-ordered array even if `then_` is not C-ordered. This breaks artificial viscosity in Mirgecom when an array context uses a Fortran style data layout. This change makes the output have the same strides as `then_` if the shape of `then_` is known, otherwise it defaults to use the same layout as `criterion`.

* Increment version

* Resolve Flake8 failures

* Use more idiomatic != in shape comparison

Co-authored-by: Andreas Klöckner <inform@tiker.net>

Fix skipping of SPIR-V test for Nvidia driver

See merge request !137

* make function also work in a subclass

* Use __class__ instead of type()

Co-authored-by: Andreas Klöckner <inform@tiker.net>

Co-authored-by: Andreas Klöckner <inform@tiker.net>