Adopt @testset syntax for PyTest.jl

[pdobacz]

It would be good if instead of @pytest one could do @testset to invoke PyTest-tests, so that PyTest features can be used as an extension to Base.Test.

But how could that work?

[s-celles]

@pdobacz maybe you should have a look at
https://github.com/JuliaLang/julia/blame/96b28d64bdd3ae037378028d4cd60e5a4c397256/HISTORY.md#L289 , see this PR JuliaLang/julia#13062
and contact someone who worked on Julia tests in Base (and particulary on testset macro) @Lainnz
Adding fixtures to Base.Test will be a great feature to have!
So maybe some other people could help on this : @aviks @quinnj @tkelman ...

PS : burrowsa/Fixtures.jl#15 is broken for Julia 0.6