Major release with new features and bug-fixes
Features:
1. Includes several new gradient-free optimizers from multiple frameworks -- Nevergrad, Pymoo, Platypus, and MOBOpt. Updated documentation to reflect new algorithms
2. Better LAMMPS support, both for spawning LAMMPS jobs and reading LAMMPS dump/output files
3. Better error handling -- Errors now generate `np.nan` objectives, instead of crashing the optimization routine
4. Ability to save and restart from previously evaluated variable sets
5. More examples for serial/parallel forcefield parameterization using LAMMPS/GULP, and parameterization of hybrid forcefields
6. Parallelization using both multiprocessing and mpi pools