fix install_requires blocker (#85)
fix install_requires blocker (#85)

jaygoldfinch/OWSLib,datagovuk/OWSLib,datagovuk/OWSLib,tomkralidis/OWSLib,kwilcox/OWSLib,jaygoldfinch/OWSLib,dblodgett-usgs/OWSLib,JuergenWeichand/OWSLib,daf/OWSLib,KeyproOy/OWSLib,daf/OWSLib,b-cube/OWSLib,ocefpaf/OWSLib,robmcmullen/OWSLib,Jenselme/OWSLib,kalxas/OWSLib,daf/OWSLib,geographika/OWSLib,bird-house/OWSLib,datagovuk/OWSLib,menegon/OWSLib,jachym/OWSLib,QuLogic/OWSLib,geopython/OWSLib,mbertrand/OWSLib,gfusca/OWSLib