TST: stats: add test of crystalball entropy
TST: stats: add test of crystalball entropy

mdhaber/scipy,grlee77/scipy,Eric89GXL/scipy,ilayn/scipy,Stefan-Endres/scipy,WarrenWeckesser/scipy,anntzer/scipy,e-q/scipy,mdhaber/scipy,vigna/scipy,perimosocordiae/scipy,WarrenWeckesser/scipy,andyfaff/scipy,scipy/scipy,scipy/scipy,matthew-brett/scipy,Eric89GXL/scipy,WarrenWeckesser/scipy,ilayn/scipy,WarrenWeckesser/scipy,mdhaber/scipy,matthew-brett/scipy,mdhaber/scipy,ilayn/scipy,Eric89GXL/scipy,tylerjereddy/scipy,Stefan-Endres/scipy,zerothi/scipy,e-q/scipy,zerothi/scipy,mdhaber/scipy,matthew-brett/scipy,grlee77/scipy,ilayn/scipy,anntzer/scipy,endolith/scipy,grlee77/scipy,andyfaff/scipy,rgommers/scipy,e-q/scipy,tylerjereddy/scipy,rgommers/scipy,scipy/scipy,tylerjereddy/scipy,vigna/scipy,WarrenWeckesser/scipy,Stefan-Endres/scipy,WarrenWeckesser/scipy,andyfaff/scipy,perimosocordiae/scipy,scipy/scipy,tylerjereddy/scipy,perimosocordiae/scipy,e-q/scipy,endolith/scipy,anntzer/scipy,grlee77/scipy,endolith/scipy,Eric89GXL/scipy,matthew-brett/scipy,perimosocordiae/scipy,e-q/scipy,zerothi/scipy,scipy/scipy,Eric89GXL/scipy,rgommers/scipy,Eric89GXL/scipy,rgommers/scipy,Stefan-Endres/scipy,anntzer/scipy,vigna/scipy,Stefan-Endres/scipy,scipy/scipy,Stefan-Endres/scipy,zerothi/scipy,mdhaber/scipy,zerothi/scipy,rgommers/scipy,endolith/scipy,anntzer/scipy,tylerjereddy/scipy,endolith/scipy,matthew-brett/scipy,andyfaff/scipy,andyfaff/scipy,perimosocordiae/scipy,andyfaff/scipy,grlee77/scipy,vigna/scipy,ilayn/scipy,ilayn/scipy,vigna/scipy,perimosocordiae/scipy,zerothi/scipy,anntzer/scipy,endolith/scipy