bumped version to 0.4.2
bumped version to 0.4.2

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