Add warning filter to doc build for distutils deprecations.
Add warning filter to doc build for distutils deprecations.

scipy/scipy,endolith/scipy,Stefan-Endres/scipy,scipy/scipy,perimosocordiae/scipy,rgommers/scipy,mdhaber/scipy,vigna/scipy,mdhaber/scipy,andyfaff/scipy,WarrenWeckesser/scipy,andyfaff/scipy,ilayn/scipy,mdhaber/scipy,ilayn/scipy,andyfaff/scipy,anntzer/scipy,rgommers/scipy,Stefan-Endres/scipy,andyfaff/scipy,ilayn/scipy,perimosocordiae/scipy,endolith/scipy,WarrenWeckesser/scipy,anntzer/scipy,Stefan-Endres/scipy,endolith/scipy,WarrenWeckesser/scipy,Stefan-Endres/scipy,WarrenWeckesser/scipy,vigna/scipy,Stefan-Endres/scipy,perimosocordiae/scipy,scipy/scipy,anntzer/scipy,ilayn/scipy,scipy/scipy,rgommers/scipy,endolith/scipy,mdhaber/scipy,endolith/scipy,anntzer/scipy,WarrenWeckesser/scipy,Stefan-Endres/scipy,perimosocordiae/scipy,WarrenWeckesser/scipy,anntzer/scipy,rgommers/scipy,perimosocordiae/scipy,ilayn/scipy,rgommers/scipy,vigna/scipy,vigna/scipy,scipy/scipy,andyfaff/scipy,perimosocordiae/scipy,scipy/scipy,mdhaber/scipy,vigna/scipy,mdhaber/scipy,anntzer/scipy,endolith/scipy,andyfaff/scipy,ilayn/scipy