Some buildSchoolGraph improvements
Some buildSchoolGraph improvements

differentmatt/codecombat,tpai/codecombat,duybkict/codecombat,differentmatt/codecombat,zhangxiuquan/codecombat,edtrist/codecombat,javatlacati/codecombat,UltCombo/codecombat,tpai/codecombat,jeremyprice/codecombat,duybkict/codecombat,codecombat/codecombat,weevilgenius/codecombat,icodegame/codecombat,codecombat/codecombat,tpai/codecombat,duybkict/codecombat,kidaa/codecombat,nimda7/codecombat,Minhir/codecombat,tpai/codecombat,javatlacati/codecombat,UltCombo/codecombat,nimda7/codecombat,Zerrien/codecombat,khoa102/codecombat,jacobakkerboom/codecombat,edtrist/codecombat,zhangxiuquan/codecombat,edtrist/codecombat,jeremyprice/codecombat,kidaa/codecombat,fabichoi/codecombat,VilkkuV/codecombat,probil/codecombat,icodegame/codecombat,Minhir/codecombat,Zerrien/codecombat,icodegame/codecombat,jeremyprice/codecombat,jacobakkerboom/codecombat,kidaa/codecombat,codecombat/codecombat,Zerrien/codecombat,probil/codecombat,javatlacati/codecombat,javatlacati/codecombat,fabichoi/codecombat,edtrist/codecombat,zhangxiuquan/codecombat,codecombat/codecombat,VilkkuV/codecombat,javatlacati/codecombat,differentmatt/codecombat,weevilgenius/codecombat,fabichoi/codecombat,UltCombo/codecombat,jeremiahyan/codecombat,Minhir/codecombat,khoa102/codecombat,jacobakkerboom/codecombat,kidaa/codecombat,probil/codecombat,UltCombo/codecombat,jeremiahyan/codecombat,nimda7/codecombat,codecombat/codecombat,nimda7/codecombat,probil/codecombat,Zerrien/codecombat,jacobakkerboom/codecombat,icodegame/codecombat,jeremiahyan/codecombat,VilkkuV/codecombat,khoa102/codecombat,VilkkuV/codecombat,fabichoi/codecombat,weevilgenius/codecombat,weevilgenius/codecombat,khoa102/codecombat,duybkict/codecombat,differentmatt/codecombat,jeremyprice/codecombat,zhangxiuquan/codecombat,jeremiahyan/codecombat,Minhir/codecombat