importlib.invalidate_caches() was introduced in Python 3.3, not 3.1
importlib.invalidate_caches() was introduced in Python 3.3, not 3.1

dpshelio/astropy-helpers,embray/astropy_helpers,bsipocz/astropy-helpers,embray/astropy_helpers,bsipocz/astropy-helpers,bsipocz/astropy-helpers,astropy/astropy-helpers,astropy/astropy-helpers,larrybradley/astropy-helpers,dpshelio/astropy-helpers,embray/astropy_helpers,larrybradley/astropy-helpers,embray/astropy_helpers,Cadair/astropy-helpers,larrybradley/astropy-helpers,Cadair/astropy-helpers