Add save_lammps function
Add save_lammps function

ctk3b/mbuild,summeraz/mbuild,tcmoore3/mbuild,Jonestj1/mbuild,sallai/mbuild,Jonestj1/mbuild,sallai/mbuild,ctk3b/mbuild,iModels/mbuild,summeraz/mbuild,iModels/mbuild,tcmoore3/mbuild