sympy/sympy — pull request #2596 by skirpichev (2013-11-14 08:53:00+00:00)
Title: change foo**(S(1)/3) to cbrt(foo) in tests

That's a remaining stuff for #2577 from [@smichr's pr](https://github.com/skirpichev/sympy/pull/4)

@smichr, sorry for delay.