Pykokkos-base

What's Changed
* CMake unity build batches + pch support + DEBUG_OUTPUT env variable by jrmadsen in https://github.com/kokkos/pykokkos-base/pull/28
* Fixes for black and test/tools.py by jrmadsen in https://github.com/kokkos/pykokkos-base/pull/33
* Support pykokkos-base as subproject with existing kokkos by jrmadsen in https://github.com/kokkos/pykokkos-base/pull/35
* Fix pip install by jrmadsen in https://github.com/kokkos/pykokkos-base/pull/36
* Random pools by jrmadsen in https://github.com/kokkos/pykokkos-base/pull/37


**Full Changelog**: https://github.com/kokkos/pykokkos-base/compare/v0.0.6...v0.0.7

- Miscellaneous fixes for non-host backends
- Fixes to free-standing `create_mirror` and `create_mirror_view`
- Member versions of `create_mirror` and `create_mirror_view` implicitly perform deep-copy

- install kokkos from submodule option
- improved compile-time
- support for `Kokkos::deep_copy(...)`
- support for `Kokkos::create_mirror(...)`
- support for `Kokkos::create_mirror_view(...)`
- support for Kokkos-Tools

- Fixes to PyPi installation
- Functions for querying the availability of layouts/traits/spaces
- `kokkos.get_layout_available(<string|enum_id>)`
- `kokkos.get_memory_space_available(<string|enum_id>)`
- `kokkos.get_memory_trait_available(<string|enum_id>)`
- Split up the compilation to improve build time

- Tags the first official release on PyPi: https://pypi.org/project/pykokkos-base/