add test to hit RankWarning in polyutils._fit
add test to hit RankWarning in polyutils._fit

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