TST: stats: rewrite tests for moment/interval kwd rename
TST: stats: rewrite tests for moment/interval kwd rename

rgommers/scipy,rgommers/scipy,Stefan-Endres/scipy,Stefan-Endres/scipy,WarrenWeckesser/scipy,endolith/scipy,mdhaber/scipy,mdhaber/scipy,scipy/scipy,endolith/scipy,vigna/scipy,scipy/scipy,andyfaff/scipy,WarrenWeckesser/scipy,endolith/scipy,andyfaff/scipy,scipy/scipy,ilayn/scipy,perimosocordiae/scipy,mdhaber/scipy,ilayn/scipy,WarrenWeckesser/scipy,anntzer/scipy,rgommers/scipy,ilayn/scipy,vigna/scipy,andyfaff/scipy,vigna/scipy,Stefan-Endres/scipy,Stefan-Endres/scipy,vigna/scipy,WarrenWeckesser/scipy,scipy/scipy,anntzer/scipy,endolith/scipy,scipy/scipy,endolith/scipy,perimosocordiae/scipy,WarrenWeckesser/scipy,anntzer/scipy,anntzer/scipy,mdhaber/scipy,andyfaff/scipy,WarrenWeckesser/scipy,ilayn/scipy,mdhaber/scipy,endolith/scipy,Stefan-Endres/scipy,rgommers/scipy,ilayn/scipy,rgommers/scipy,perimosocordiae/scipy,andyfaff/scipy,ilayn/scipy,mdhaber/scipy,scipy/scipy,Stefan-Endres/scipy,perimosocordiae/scipy,anntzer/scipy,anntzer/scipy,andyfaff/scipy,perimosocordiae/scipy,vigna/scipy,perimosocordiae/scipy