add rem2pi test

Author: jrevels

test/MiscTest.jl

@@ -136,6 +136,10 @@ for i in 1:3, j in 1:3
     i != j && (@test h[i, j] ≈ 0.0)
 end
 
+########
+# misc #
+########
+
 # issue 267
 @noinline f267(z, x) = x[1]
 z267 = ([(1, (2), [(3, (4, 5, [1, 2, (3, (4, 5), [5])]), (5))])])
@@ -145,4 +149,8 @@ let z = z267
     @test ForwardDiff.hessian(h, [1.]) == zeros(1, 1)
 end
 
-end
+# issue #290
+@test ForwardDiff.derivative(x -> rem2pi(x, RoundUp), rand()) == 1
+@test ForwardDiff.derivative(x -> rem2pi(x, RoundDown), rand()) == 1
+
+end # module