* kokkos: update kokkos spackage to add current host/gpu architectures.
* kokkos: simplify host/gpu architecture selection and make intent of arg population logic more clear.
* kokkos: mollify flake8.
* Make strings and logic more pythonic. Add error for GPU arch without CUDA.
* kokkos: simplify conflicts behaviour. make args population more pythonic.
* kokkos: move gpu values to list for use in variant and conflicts checking.
* kokkos: How fortunate the man with None.
* kokkos: fix gpu_arch conflict loop error. add conflict to guard against +cuda and 2.5.00:develop versions, until kokkos issue #1296 is resolved.
* kokkos: mollify flake8.
* kokkos: add descriptive message to version conflict with +cuda.
fdb2d6f493