MAINT: Remove y_old from BDF solver
MAINT: Remove y_old from BDF solver

aarchiba/scipy,e-q/scipy,scipy/scipy,lhilt/scipy,nmayorov/scipy,lhilt/scipy,jamestwebber/scipy,anntzer/scipy,pizzathief/scipy,Stefan-Endres/scipy,anntzer/scipy,befelix/scipy,jjhelmus/scipy,gfyoung/scipy,pbrod/scipy,andyfaff/scipy,gfyoung/scipy,nmayorov/scipy,matthew-brett/scipy,endolith/scipy,vigna/scipy,befelix/scipy,aarchiba/scipy,WarrenWeckesser/scipy,pizzathief/scipy,scipy/scipy,jor-/scipy,nmayorov/scipy,arokem/scipy,grlee77/scipy,Eric89GXL/scipy,jjhelmus/scipy,perimosocordiae/scipy,scipy/scipy,e-q/scipy,jjhelmus/scipy,Eric89GXL/scipy,josephcslater/scipy,aeklant/scipy,zerothi/scipy,jamestwebber/scipy,zerothi/scipy,tylerjereddy/scipy,josephcslater/scipy,aarchiba/scipy,aeklant/scipy,josephcslater/scipy,befelix/scipy,jjhelmus/scipy,matthew-brett/scipy,endolith/scipy,gertingold/scipy,rgommers/scipy,apbard/scipy,pbrod/scipy,matthew-brett/scipy,gfyoung/scipy,WarrenWeckesser/scipy,arokem/scipy,pbrod/scipy,nmayorov/scipy,Eric89GXL/scipy,perimosocordiae/scipy,pizzathief/scipy,WarrenWeckesser/scipy,endolith/scipy,arokem/scipy,josephcslater/scipy,mdhaber/scipy,perimosocordiae/scipy,anntzer/scipy,rgommers/scipy,apbard/scipy,WarrenWeckesser/scipy,aeklant/scipy,lhilt/scipy,aeklant/scipy,pizzathief/scipy,endolith/scipy,vigna/scipy,jamestwebber/scipy,apbard/scipy,ilayn/scipy,pbrod/scipy,andyfaff/scipy,Stefan-Endres/scipy,matthew-brett/scipy,gertingold/scipy,aarchiba/scipy,jamestwebber/scipy,apbard/scipy,person142/scipy,tylerjereddy/scipy,Stefan-Endres/scipy,mdhaber/scipy,zerothi/scipy,befelix/scipy,jor-/scipy,e-q/scipy,andyfaff/scipy,vigna/scipy,jor-/scipy,befelix/scipy,WarrenWeckesser/scipy,Stefan-Endres/scipy,rgommers/scipy,jor-/scipy,person142/scipy,ilayn/scipy,perimosocordiae/scipy,Eric89GXL/scipy,person142/scipy,jamestwebber/scipy,tylerjereddy/scipy,gfyoung/scipy,lhilt/scipy,zerothi/scipy,endolith/scipy,anntzer/scipy,Eric89GXL/scipy,mdhaber/scipy,perimosocordiae/scipy,arokem/scipy,Stefan-Endres/scipy,mdhaber/scipy,nmayorov/scipy,e-q/scipy,e-q/scipy,anntzer/scipy,apbard/scipy,Eric89GXL/scipy,WarrenWeckesser/scipy,pizzathief/scipy,Stefan-Endres/scipy,scipy/scipy,zerothi/scipy,ilayn/scipy,andyfaff/scipy,mdhaber/scipy,tylerjereddy/scipy,rgommers/scipy,vigna/scipy,ilayn/scipy,mdhaber/scipy,pbrod/scipy,aeklant/scipy,arokem/scipy,scipy/scipy,gertingold/scipy,jor-/scipy,zerothi/scipy,tylerjereddy/scipy,grlee77/scipy,endolith/scipy,person142/scipy,aarchiba/scipy,grlee77/scipy,grlee77/scipy,andyfaff/scipy,scipy/scipy,gfyoung/scipy,ilayn/scipy,gertingold/scipy,pbrod/scipy,ilayn/scipy,perimosocordiae/scipy,rgommers/scipy,josephcslater/scipy,person142/scipy,andyfaff/scipy,grlee77/scipy,jjhelmus/scipy,gertingold/scipy,matthew-brett/scipy,vigna/scipy,anntzer/scipy,lhilt/scipy