Merlin-spellbook

Added
- Ability for `conduit-translate` to deal with chunks from `conduit-collect`.
- Ansynchronous parallelism for `conduit-translate -chunks -n <n processes>`.

Fixed
- Help message for `-chunk_size` in `conduit-collect`. Previously was ambiguous,
saying `-chunk_size` corresponded to number of files, instead of size of files.
- Typo in `make-samples` help message.
- Error in serializing booleans
- Bug in serializer and error in serialize testing

Fixed
- Allowed for pyDOE2 sampling functions to use seeds.
- Bug in `spellbook learn` that excluded the `-regressor` flag.

Fixed
- A conduit loading bug.

Added
- CLI test for `spellbook serialize`.
- CLI test for `spellbook make-samples`.
- Conduit bundler unit tests.

Fixed
- A variety of bugs in `conduit-collect` and `conduit-translate`.

Added
- The new spellbook command `spellbook serialize`.
- The new spellbook command `spellbook conduit-collect`.
- The new spellbook command `spellbook conduit-translate`.

Changed
- For better organization and speed, moved internal cli logic from `argparse` to `click`.

Added
- Central composite sampling in `make-samples`.