class for build isometries in spritekit swift 4.0
example with a isometric texture:
texture : https://kenney.nl/assets/isometric-buildings
tutorial: https://gamedevelopment.tutsplus.com/tutorials/creating-isometric-worlds-a-primer-for-game-developers--gamedev-6511
tutorial: http://bigspritegames.com/isometric-tile-based-game-part-1/