Alternative idea--use find_module to locate the path for the six module--looking first for the unadorned 'six' module that would be found on sys.path, and failing that looking up 'astropy.extern.bundled.six'.  Then load that module using the load_module machinery, but giving it the new name 'astropy.extern.six'.  That makes everything 'just work' and is compatible with six's own sys.modules games.
Alternative idea--use find_module to locate the path for the six module--looking first for the unadorned 'six' module that would be found on sys.path, and failing that looking up 'astropy.extern.bundled.six'.  Then load that module using the load_module machinery, but giving it the new name 'astropy.extern.six'.  That makes everything 'just work' and is compatible with six's own sys.modules games.

saimn/astropy,funbaker/astropy,larrybradley/astropy,StuartLittlefair/astropy,dhomeier/astropy,lpsinger/astropy,stargaser/astropy,MSeifert04/astropy,stargaser/astropy,aleksandr-bakanov/astropy,funbaker/astropy,tbabej/astropy,pllim/astropy,pllim/astropy,saimn/astropy,kelle/astropy,dhomeier/astropy,joergdietrich/astropy,joergdietrich/astropy,AustereCuriosity/astropy,lpsinger/astropy,DougBurke/astropy,joergdietrich/astropy,MSeifert04/astropy,pllim/astropy,StuartLittlefair/astropy,funbaker/astropy,dhomeier/astropy,bsipocz/astropy,stargaser/astropy,bsipocz/astropy,larrybradley/astropy,tbabej/astropy,aleksandr-bakanov/astropy,tbabej/astropy,kelle/astropy,MSeifert04/astropy,larrybradley/astropy,aleksandr-bakanov/astropy,AustereCuriosity/astropy,saimn/astropy,mhvk/astropy,lpsinger/astropy,StuartLittlefair/astropy,MSeifert04/astropy,AustereCuriosity/astropy,astropy/astropy,larrybradley/astropy,pllim/astropy,astropy/astropy,kelle/astropy,kelle/astropy,AustereCuriosity/astropy,DougBurke/astropy,saimn/astropy,DougBurke/astropy,dhomeier/astropy,kelle/astropy,saimn/astropy,larrybradley/astropy,AustereCuriosity/astropy,mhvk/astropy,DougBurke/astropy,lpsinger/astropy,mhvk/astropy,lpsinger/astropy,joergdietrich/astropy,bsipocz/astropy,aleksandr-bakanov/astropy,pllim/astropy,StuartLittlefair/astropy,mhvk/astropy,joergdietrich/astropy,stargaser/astropy,funbaker/astropy,mhvk/astropy,astropy/astropy,dhomeier/astropy,tbabej/astropy,astropy/astropy,tbabej/astropy,astropy/astropy,bsipocz/astropy,StuartLittlefair/astropy