TST: optimize: hopefully fixed segfault issue
TST: optimize: hopefully fixed segfault issue

test_unbounded_below_no_presolve was passing cho_factor an empty array.
This was not a problem locally, but caused a segfault on TravisCI.
Set option "cholesky":False for that test.

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