Interpolation Operator Accuracy

[JaredCrean2]

Using this code:

      sbp = TetSBP{Float64}(degree=order, reorder=false, internal=false)
      ref_verts = sbp.vtx
      println("ref_verts = \n", ref_verts)
      interp_op = SummationByParts.buildinterpolation(sbp, ref_verts.')
      println("interp_op = \n", interp_op)

produces an interpolation operator that is not the identity matrix for a SBP Gamma element of degree 3 or greater.