Add test for CUDA binarycrossentropy

test/cuda/cuda.jl

@@ -31,6 +31,10 @@ cx = gpu(x)
 @test Flux.crossentropy(x,x, weight=1.0) ≈ Flux.crossentropy(cx,cx, weight=1.0)
 @test Flux.crossentropy(x,x, weight=[1.0;2.0;3.0]) ≈ Flux.crossentropy(cx,cx, weight=cu([1.0;2.0;3.0]))
 
+x = σ.([-1.1491, 0.8619, 0.3127])
+y = [1, 1, 0.]
+@test Flux.binarycrossentropy.(x,y) ≈ Flux.binarycrossentropy.(cu(x),cu(y))
+
 xs = rand(5, 5)
 ys = Flux.onehotbatch(1:5,1:5)
 @test collect(cu(xs) .+ cu(ys)) ≈ collect(xs .+ ys)