Distributed Julia crush tests return zeros

[GregPlowman]

Julia crush tests (smallcrushJulia and bigcrushJulia) internally use pmap.
When distributed workers are available, these tests work as expected.
However, when additional workers are available, the tests for WrappedRNG{<:Integer} return zeros.

using Distributed
addprocs(4);

using Random
using RNGTest

RNGTest.smallcrushJulia(rand)                               # works as expected
RNGTest.smallcrushJulia(RNGTest.wrap(Xoshiro(), Float64))   # works as expected
RNGTest.smallcrushJulia(RNGTest.wrap(Xoshiro(), UInt64))    # fails, returns zeros

[andreasnoack]

Should be fixed by #31