skip doctest lines that modify global state of Galactocentric frame attributes
skip doctest lines that modify global state of Galactocentric frame attributes

saimn/astropy,StuartLittlefair/astropy,StuartLittlefair/astropy,pllim/astropy,dhomeier/astropy,saimn/astropy,StuartLittlefair/astropy,lpsinger/astropy,dhomeier/astropy,mhvk/astropy,saimn/astropy,larrybradley/astropy,mhvk/astropy,lpsinger/astropy,dhomeier/astropy,saimn/astropy,astropy/astropy,dhomeier/astropy,lpsinger/astropy,astropy/astropy,lpsinger/astropy,pllim/astropy,pllim/astropy,astropy/astropy,aleksandr-bakanov/astropy,lpsinger/astropy,mhvk/astropy,mhvk/astropy,aleksandr-bakanov/astropy,astropy/astropy,larrybradley/astropy,pllim/astropy,aleksandr-bakanov/astropy,StuartLittlefair/astropy,larrybradley/astropy,StuartLittlefair/astropy,astropy/astropy,saimn/astropy,larrybradley/astropy,dhomeier/astropy,mhvk/astropy,aleksandr-bakanov/astropy,larrybradley/astropy,pllim/astropy