TST: Parametrize and break apart dtype tests
TST: Parametrize and break apart dtype tests

Now that we're using parametrize, may as well drop it in a few more places

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