Fix OSX build; remove NumPy 1.13 and 1.14
Fix OSX build; remove NumPy 1.13 and 1.14

scikit-xray/scikit-xray,tacaswell/scikit-beam,scikit-xray/scikit-xray,Nikea/scikit-xray,tacaswell/scikit-beam,tacaswell/scikit-beam,Nikea/scikit-xray,scikit-xray/scikit-xray,Nikea/scikit-xray,tacaswell/scikit-xray,tacaswell/scikit-xray,tacaswell/scikit-xray