AppVeyor: skip sphinx tests since graphviz cannot currently be installed
AppVeyor: skip sphinx tests since graphviz cannot currently be installed
astropy/astropy-helpers,bsipocz/astropy-helpers,bsipocz/astropy-helpers,larrybradley/astropy-helpers,Cadair/astropy-helpers,larrybradley/astropy-helpers,astropy/astropy-helpers,dpshelio/astropy-helpers,Cadair/astropy-helpers,dpshelio/astropy-helpers,larrybradley/astropy-helpers,bsipocz/astropy-helpers