[TST] linalg.hessenberg: add unit test
[TST] linalg.hessenberg: add unit test

add the example from #3364 as unit test.

gfyoung/scipy,WarrenWeckesser/scipy,Gillu13/scipy,hainm/scipy,gdooper/scipy,cpaulik/scipy,nmayorov/scipy,dominicelse/scipy,gef756/scipy,vigna/scipy,mgaitan/scipy,behzadnouri/scipy,perimosocordiae/scipy,sauliusl/scipy,Gillu13/scipy,matthew-brett/scipy,ndchorley/scipy,minhlongdo/scipy,e-q/scipy,ChanderG/scipy,scipy/scipy,Newman101/scipy,petebachant/scipy,mikebenfield/scipy,maciejkula/scipy,scipy/scipy,gfyoung/scipy,Eric89GXL/scipy,petebachant/scipy,scipy/scipy,Srisai85/scipy,mtrbean/scipy,rmcgibbo/scipy,rgommers/scipy,haudren/scipy,jor-/scipy,tylerjereddy/scipy,raoulbq/scipy,Stefan-Endres/scipy,behzadnouri/scipy,mdhaber/scipy,FRidh/scipy,woodscn/scipy,efiring/scipy,e-q/scipy,ndchorley/scipy,ilayn/scipy,aman-iitj/scipy,lukauskas/scipy,zxsted/scipy,vanpact/scipy,befelix/scipy,pnedunuri/scipy,fredrikw/scipy,chatcannon/scipy,zerothi/scipy,rgommers/scipy,felipebetancur/scipy,lukauskas/scipy,witcxc/scipy,vhaasteren/scipy,gertingold/scipy,matthew-brett/scipy,FRidh/scipy,vigna/scipy,apbard/scipy,giorgiop/scipy,mikebenfield/scipy,WillieMaddox/scipy,woodscn/scipy,jjhelmus/scipy,Kamp9/scipy,witcxc/scipy,argriffing/scipy,trankmichael/scipy,grlee77/scipy,larsmans/scipy,WillieMaddox/scipy,hainm/scipy,Srisai85/scipy,vhaasteren/scipy,aarchiba/scipy,andim/scipy,apbard/scipy,Newman101/scipy,mortada/scipy,jseabold/scipy,zaxliu/scipy,scipy/scipy,kleskjr/scipy,anielsen001/scipy,ortylp/scipy,ChanderG/scipy,Stefan-Endres/scipy,zxsted/scipy,kalvdans/scipy,apbard/scipy,zerothi/scipy,hainm/scipy,kleskjr/scipy,arokem/scipy,sriki18/scipy,FRidh/scipy,petebachant/scipy,petebachant/scipy,person142/scipy,pizzathief/scipy,behzadnouri/scipy,zerothi/scipy,jonycgn/scipy,Kamp9/scipy,maciejkula/scipy,nvoron23/scipy,anntzer/scipy,mtrbean/scipy,e-q/scipy,arokem/scipy,pyramania/scipy,tylerjereddy/scipy,befelix/scipy,befelix/scipy,kleskjr/scipy,richardotis/scipy,gef756/scipy,newemailjdm/scipy,futurulus/scipy,Gillu13/scipy,pschella/scipy,mgaitan/scipy,pnedunuri/scipy,FRidh/scipy,rgommers/scipy,niknow/scipy,zerothi/scipy,vberaudi/scipy,zaxliu/scipy,minhlongdo/scipy,sriki18/scipy,perimosocordiae/scipy,pbrod/scipy,Gillu13/scipy,perimosocordiae/scipy,woodscn/scipy,fredrikw/scipy,piyush0609/scipy,anielsen001/scipy,lukauskas/scipy,pizzathief/scipy,gdooper/scipy,dch312/scipy,nmayorov/scipy,matthewalbani/scipy,jjhelmus/scipy,zaxliu/scipy,endolith/scipy,ilayn/scipy,scipy/scipy,grlee77/scipy,aman-iitj/scipy,Dapid/scipy,arokem/scipy,mingwpy/scipy,dch312/scipy,nonhermitian/scipy,Srisai85/scipy,gdooper/scipy,pyramania/scipy,Eric89GXL/scipy,kalvdans/scipy,mortada/scipy,WarrenWeckesser/scipy,richardotis/scipy,Srisai85/scipy,WillieMaddox/scipy,gfyoung/scipy,pizzathief/scipy,gertingold/scipy,ilayn/scipy,rmcgibbo/scipy,nvoron23/scipy,fernand/scipy,dch312/scipy,maniteja123/scipy,andim/scipy,witcxc/scipy,pbrod/scipy,sonnyhu/scipy,nmayorov/scipy,aeklant/scipy,ales-erjavec/scipy,apbard/scipy,haudren/scipy,anntzer/scipy,minhlongdo/scipy,chatcannon/scipy,zaxliu/scipy,josephcslater/scipy,vanpact/scipy,befelix/scipy,mikebenfield/scipy,felipebetancur/scipy,efiring/scipy,anielsen001/scipy,e-q/scipy,futurulus/scipy,rgommers/scipy,grlee77/scipy,pschella/scipy,Dapid/scipy,vigna/scipy,anntzer/scipy,sonnyhu/scipy,njwilson23/scipy,anntzer/scipy,gertingold/scipy,gfyoung/scipy,jamestwebber/scipy,Srisai85/scipy,mdhaber/scipy,woodscn/scipy,cpaulik/scipy,jseabold/scipy,andyfaff/scipy,andyfaff/scipy,mingwpy/scipy,matthewalbani/scipy,josephcslater/scipy,efiring/scipy,andim/scipy,nvoron23/scipy,mdhaber/scipy,maciejkula/scipy,endolith/scipy,ales-erjavec/scipy,richardotis/scipy,piyush0609/scipy,vhaasteren/scipy,sriki18/scipy,zxsted/scipy,andyfaff/scipy,jakevdp/scipy,josephcslater/scipy,newemailjdm/scipy,ChanderG/scipy,Stefan-Endres/scipy,newemailjdm/scipy,andyfaff/scipy,aarchiba/scipy,mortada/scipy,futurulus/scipy,futurulus/scipy,WarrenWeckesser/scipy,rmcgibbo/scipy,rmcgibbo/scipy,mhogg/scipy,jsilter/scipy,raoulbq/scipy,maniteja123/scipy,nvoron23/scipy,anielsen001/scipy,mikebenfield/scipy,mhogg/scipy,mortada/scipy,ilayn/scipy,sriki18/scipy,aeklant/scipy,haudren/scipy,matthew-brett/scipy,jseabold/scipy,ChanderG/scipy,dch312/scipy,andyfaff/scipy,mingwpy/scipy,ortylp/scipy,person142/scipy,cpaulik/scipy,jsilter/scipy,vanpact/scipy,sriki18/scipy,aarchiba/scipy,giorgiop/scipy,jseabold/scipy,nonhermitian/scipy,jonycgn/scipy,surhudm/scipy,lhilt/scipy,argriffing/scipy,surhudm/scipy,mikebenfield/scipy,arokem/scipy,larsmans/scipy,niknow/scipy,pbrod/scipy,chatcannon/scipy,futurulus/scipy,mortonjt/scipy,aman-iitj/scipy,surhudm/scipy,woodscn/scipy,efiring/scipy,mhogg/scipy,Kamp9/scipy,minhlongdo/scipy,petebachant/scipy,mortada/scipy,ortylp/scipy,mgaitan/scipy,gdooper/scipy,maniteja123/scipy,jseabold/scipy,person142/scipy,gertingold/scipy,hainm/scipy,richardotis/scipy,matthewalbani/scipy,pschella/scipy,tylerjereddy/scipy,aman-iitj/scipy,vhaasteren/scipy,WarrenWeckesser/scipy,mhogg/scipy,ales-erjavec/scipy,sauliusl/scipy,minhlongdo/scipy,kalvdans/scipy,nvoron23/scipy,grlee77/scipy,zerothi/scipy,nvoron23/scipy,pbrod/scipy,njwilson23/scipy,gef756/scipy,zaxliu/scipy,Shaswat27/scipy,pschella/scipy,niknow/scipy,jakevdp/scipy,kleskjr/scipy,Dapid/scipy,josephcslater/scipy,WillieMaddox/scipy,lhilt/scipy,pizzathief/scipy,Shaswat27/scipy,behzadnouri/scipy,jsilter/scipy,raoulbq/scipy,perimosocordiae/scipy,lhilt/scipy,kalvdans/scipy,fernand/scipy,scipy/scipy,fredrikw/scipy,fernand/scipy,giorgiop/scipy,matthew-brett/scipy,Shaswat27/scipy,mortonjt/scipy,perimosocordiae/scipy,rmcgibbo/scipy,maciejkula/scipy,jor-/scipy,matthewalbani/scipy,arokem/scipy,WillieMaddox/scipy,jsilter/scipy,vberaudi/scipy,ndchorley/scipy,chatcannon/scipy,trankmichael/scipy,Gillu13/scipy,bkendzior/scipy,mtrbean/scipy,bkendzior/scipy,gfyoung/scipy,ndchorley/scipy,vberaudi/scipy,efiring/scipy,aarchiba/scipy,Eric89GXL/scipy,surhudm/scipy,chatcannon/scipy,jsilter/scipy,tylerjereddy/scipy,efiring/scipy,newemailjdm/scipy,jonycgn/scipy,Kamp9/scipy,jor-/scipy,piyush0609/scipy,Eric89GXL/scipy,mingwpy/scipy,sonnyhu/scipy,WillieMaddox/scipy,ortylp/scipy,felipebetancur/scipy,jamestwebber/scipy,WarrenWeckesser/scipy,vberaudi/scipy,raoulbq/scipy,witcxc/scipy,nmayorov/scipy,dominicelse/scipy,jakevdp/scipy,FRidh/scipy,fredrikw/scipy,argriffing/scipy,giorgiop/scipy,piyush0609/scipy,trankmichael/scipy,jamestwebber/scipy,Gillu13/scipy,behzadnouri/scipy,mtrbean/scipy,matthew-brett/scipy,Eric89GXL/scipy,Dapid/scipy,person142/scipy,behzadnouri/scipy,giorgiop/scipy,felipebetancur/scipy,niknow/scipy,piyush0609/scipy,mdhaber/scipy,fernand/scipy,andim/scipy,larsmans/scipy,Dapid/scipy,ortylp/scipy,Kamp9/scipy,haudren/scipy,pnedunuri/scipy,sauliusl/scipy,befelix/scipy,sonnyhu/scipy,nonhermitian/scipy,richardotis/scipy,jonycgn/scipy,Shaswat27/scipy,njwilson23/scipy,jor-/scipy,minhlongdo/scipy,josephcslater/scipy,aeklant/scipy,jjhelmus/scipy,bkendzior/scipy,sauliusl/scipy,giorgiop/scipy,kleskjr/scipy,jjhelmus/scipy,grlee77/scipy,mhogg/scipy,mortonjt/scipy,dominicelse/scipy,tylerjereddy/scipy,surhudm/scipy,ndchorley/scipy,mortonjt/scipy,ales-erjavec/scipy,ilayn/scipy,ales-erjavec/scipy,chatcannon/scipy,e-q/scipy,ales-erjavec/scipy,andim/scipy,argriffing/scipy,Shaswat27/scipy,vhaasteren/scipy,niknow/scipy,ndchorley/scipy,lukauskas/scipy,trankmichael/scipy,rgommers/scipy,mgaitan/scipy,richardotis/scipy,dominicelse/scipy,fernand/scipy,witcxc/scipy,Srisai85/scipy,pyramania/scipy,Newman101/scipy,futurulus/scipy,hainm/scipy,sriki18/scipy,pnedunuri/scipy,gertingold/scipy,vberaudi/scipy,vhaasteren/scipy,mortonjt/scipy,larsmans/scipy,cpaulik/scipy,rmcgibbo/scipy,gef756/scipy,pyramania/scipy,nonhermitian/scipy,vanpact/scipy,nmayorov/scipy,Eric89GXL/scipy,argriffing/scipy,anntzer/scipy,kleskjr/scipy,Newman101/scipy,sonnyhu/scipy,Newman101/scipy,dch312/scipy,endolith/scipy,zxsted/scipy,raoulbq/scipy,andim/scipy,argriffing/scipy,fredrikw/scipy,lhilt/scipy,perimosocordiae/scipy,vigna/scipy,Stefan-Endres/scipy,jamestwebber/scipy,zxsted/scipy,jonycgn/scipy,aeklant/scipy,anielsen001/scipy,Stefan-Endres/scipy,fredrikw/scipy,anielsen001/scipy,mingwpy/scipy,endolith/scipy,aeklant/scipy,jamestwebber/scipy,Stefan-Endres/scipy,sauliusl/scipy,zaxliu/scipy,lhilt/scipy,matthewalbani/scipy,ChanderG/scipy,trankmichael/scipy,hainm/scipy,newemailjdm/scipy,pbrod/scipy,njwilson23/scipy,endolith/scipy,vberaudi/scipy,pnedunuri/scipy,trankmichael/scipy,aarchiba/scipy,njwilson23/scipy,gef756/scipy,vanpact/scipy,pnedunuri/scipy,sonnyhu/scipy,pschella/scipy,WarrenWeckesser/scipy,pbrod/scipy,larsmans/scipy,FRidh/scipy,kalvdans/scipy,bkendzior/scipy,Kamp9/scipy,jakevdp/scipy,lukauskas/scipy,niknow/scipy,larsmans/scipy,person142/scipy,jakevdp/scipy,mdhaber/scipy,surhudm/scipy,haudren/scipy,njwilson23/scipy,dominicelse/scipy,raoulbq/scipy,gdooper/scipy,aman-iitj/scipy,haudren/scipy,vanpact/scipy,mtrbean/scipy,ortylp/scipy,apbard/scipy,mtrbean/scipy,Dapid/scipy,mhogg/scipy,jonycgn/scipy,anntzer/scipy,felipebetancur/scipy,ChanderG/scipy,zerothi/scipy,pizzathief/scipy,gef756/scipy,mortonjt/scipy,piyush0609/scipy,woodscn/scipy,mdhaber/scipy,felipebetancur/scipy,sauliusl/scipy,ilayn/scipy,mingwpy/scipy,mgaitan/scipy,bkendzior/scipy,maniteja123/scipy,jor-/scipy,fernand/scipy,Newman101/scipy,jjhelmus/scipy,endolith/scipy,mgaitan/scipy,Shaswat27/scipy,maciejkula/scipy,maniteja123/scipy,pyramania/scipy,vigna/scipy,newemailjdm/scipy,jseabold/scipy,zxsted/scipy,andyfaff/scipy,nonhermitian/scipy,aman-iitj/scipy,mortada/scipy,cpaulik/scipy,maniteja123/scipy,cpaulik/scipy,lukauskas/scipy,petebachant/scipy