Revert "REL: Setup maintenance/1.15.x branch."
Revert "REL: Setup maintenance/1.15.x branch."

Oops, this reverts commit 999b4ddc64c9bda4eb58f0feda801835d34de94e.

charris/numpy,pizzathief/numpy,anntzer/numpy,shoyer/numpy,MSeifert04/numpy,charris/numpy,mhvk/numpy,charris/numpy,shoyer/numpy,MSeifert04/numpy,anntzer/numpy,WarrenWeckesser/numpy,grlee77/numpy,endolith/numpy,seberg/numpy,madphysicist/numpy,madphysicist/numpy,grlee77/numpy,pbrod/numpy,rgommers/numpy,anntzer/numpy,jakirkham/numpy,jorisvandenbossche/numpy,shoyer/numpy,jakirkham/numpy,mhvk/numpy,mattip/numpy,simongibbons/numpy,pizzathief/numpy,ahaldane/numpy,pbrod/numpy,rgommers/numpy,MSeifert04/numpy,pdebuyl/numpy,ahaldane/numpy,abalkin/numpy,pizzathief/numpy,Eric89GXL/numpy,simongibbons/numpy,endolith/numpy,Eric89GXL/numpy,numpy/numpy,anntzer/numpy,pdebuyl/numpy,MSeifert04/numpy,pizzathief/numpy,rgommers/numpy,abalkin/numpy,jorisvandenbossche/numpy,mattip/numpy,mhvk/numpy,simongibbons/numpy,WarrenWeckesser/numpy,ahaldane/numpy,seberg/numpy,gfyoung/numpy,mattip/numpy,jorisvandenbossche/numpy,Eric89GXL/numpy,madphysicist/numpy,jakirkham/numpy,pdebuyl/numpy,madphysicist/numpy,gfyoung/numpy,numpy/numpy,jakirkham/numpy,pdebuyl/numpy,WarrenWeckesser/numpy,endolith/numpy,seberg/numpy,grlee77/numpy,WarrenWeckesser/numpy,rgommers/numpy,pizzathief/numpy,jakirkham/numpy,WarrenWeckesser/numpy,pbrod/numpy,ahaldane/numpy,gfyoung/numpy,numpy/numpy,pbrod/numpy,jorisvandenbossche/numpy,mhvk/numpy,jorisvandenbossche/numpy,pbrod/numpy,mattip/numpy,abalkin/numpy,shoyer/numpy,shoyer/numpy,simongibbons/numpy,seberg/numpy,grlee77/numpy,numpy/numpy,grlee77/numpy,madphysicist/numpy,charris/numpy,ahaldane/numpy,endolith/numpy,simongibbons/numpy,Eric89GXL/numpy,mhvk/numpy,MSeifert04/numpy