TST: add regression test with complex input for signal.step.
TST: add regression test with complex input for signal.step.

Note that step2/impulse/impulse2 don't work with this input (see gh-2654).

When unifying step/step2 and impulse/impulse2, a decision should be made on
whether complex inputs need to be supported.

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