Added testing for 3D textures
Added testing for 3D textures

ghisvail/vispy,bollu/vispy,QuLogic/vispy,ghisvail/vispy,drufat/vispy,michaelaye/vispy,dchilds7/Deysha-Star-Formation,michaelaye/vispy,QuLogic/vispy,jay3sh/vispy,Eric89GXL/vispy,sh4wn/vispy,bollu/vispy,drufat/vispy,sbtlaarzc/vispy,RebeccaWPerry/vispy,ghisvail/vispy,jay3sh/vispy,kkuunnddaannkk/vispy,michaelaye/vispy,jdreaver/vispy,sh4wn/vispy,dchilds7/Deysha-Star-Formation,inclement/vispy,sbtlaarzc/vispy,jay3sh/vispy,RebeccaWPerry/vispy,drufat/vispy,sbtlaarzc/vispy,inclement/vispy,hronoses/vispy,hronoses/vispy,Eric89GXL/vispy,julienr/vispy,jdreaver/vispy,julienr/vispy,julienr/vispy,hronoses/vispy,inclement/vispy,RebeccaWPerry/vispy,jdreaver/vispy,dchilds7/Deysha-Star-Formation,Eric89GXL/vispy,srinathv/vispy,bollu/vispy,srinathv/vispy,srinathv/vispy,sh4wn/vispy,kkuunnddaannkk/vispy,kkuunnddaannkk/vispy,QuLogic/vispy