Further revisions to the method argument in the cbc_design() function.
Added the "random" and "dopt" methods.
Added restrictions so that orthogonal designs cannot use the label argument or restricted profile sets (as either of these would result in a non-orthogonal design).
This PR contains all changes for v0.5.0:
methodargument in thecbc_design()function."random"and"dopt"methods.labelargument or restricted profile sets (as either of these would result in a non-orthogonal design).