* Make nodal reductions mpi-aware

* Add clarifying remark for nodal reductions

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

* Use timestep estimation in mpi wave test

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

Grudge Refactoring

Update time-step utility functions

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

* Use mpi4py from conda for tests

* Drop "insecure" flag from curl in Github CI

* Drop "insecure" flag from curl in Gitlab CI

* Simplify WADG mass inverse

* Test mass inverse on warped geometry

* Always WADG all the time also for symbolic

* Fold test_nonaffine_mass_operator_inverse into test_mass_operator_inverse

Co-authored-by: Thomas Gibson <gibsonthomas1120@hotmail.com>