MT1D example failing on numpy 1.17.1

[lheagy]

The MT1D inversion example fails on numpy 1.17.1, so we removed it in #807. I have started a working pr, #815 to bring it back.

The MT1D inversion example is failing

Unexpected failing examples:
  File "<path to SimPEG>/simpeg/examples/08-nsem/plot_inversion_MT1D.py", line 133, in run
    fig = NSEM.Utils.dataUtils.plotMT1DModelData(problem, [mopt])
  File "<path to SimPEG>/SimPEG/EM/NSEM/Utils/dataUtils.py", line 344, in plotMT1DModelData
    loc = rec_to_ndarr(np.unique(data1D[['x', 'y']]).copy())
  File "<path to SimPEG>/SimPEG/EM/NSEM/Utils/dataUtils.py", line 266, in rec_to_ndarr
    return rec_arr.copy().view((data_type, len(rec_arr.dtype.names)))
ValueError: Changing the dtype to a subarray type is only supported if the total itemsize is unchanged