BENCH: Improve fft benchmark output when modules are missing
BENCH: Improve fft benchmark output when modules are missing

By raiseing NotImplementedError we indicate to asv to skip the benchmark without
creating lots of error messages.

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