Figured out a better way to reseed and already
instatiated Optuna sampler. I was overwriting the
RNG state in a hacky way before. I didn't realize there
was a reseed_rng() method on the the base sampler class
that can be called when the seed is re-initialized.

Test for CMA-ES sampler was actually just falling back
to RandomSampler. I just want to test things work with
another sampler so I switched to QMCSampler because it
also supports 1D search spaces.

Added support for passing kwargs to un-instantiated
optuna sampler.