Added test for ExpDecay

test/optimise.jl

@@ -53,3 +53,22 @@ end
   cbs()
   @test x == 1
 end
+
+@testset "ExpDecay" begin
+    w = randn(10, 10)
+    o = ExpDecay(0.1, decay = 0.1, decay_step = 1000, clip = 1e-4)
+    w1 = param(randn(10,10))
+    loss(x) = Flux.mse(w*x, w1*x)
+    flag = 1
+    for t = 1:10^5
+      l = loss(rand(10))
+      back!(l)
+      prev_grad = collect(w1.grad)
+      delta = Optimise.apply!(o, w1.data, w1.grad)
+      array = fill(o.eta, size(prev_grad))
+      if array .* prev_grad != delta
+        flag = 0
+      end
+    end
+    @test flag == 1
+end