Fix a divide by zero error in Scenic.Color

Author: axelson

lib/scenic/color.ex

@@ -535,7 +535,7 @@ defmodule Scenic.Color do
 
     s =
       case delta do
-        0 -> 0
+        0.0 -> 0.0
         d -> d / (1 - abs(2 * l - 1))
       end
 

test/scenic/color_test.exs

@@ -175,6 +175,12 @@ defmodule Scenic.ColorTest do
     assert Color.to_hsl({:color_hsl, {1.1, 1.2, 1.3}}) == {:color_hsl, {1.1, 1.2, 1.3}}
   end
 
+  test "white hsl to hsv to rgb" do
+    assert Color.to_hsv(:white)
+           |> Color.to_hsl()
+           |> Color.to_rgb() == {:color_rgb, {255, 255, 255}}
+  end
+
   test "named looks right" do
     Color.named()
     |> Enum.each(fn {n, {r, g, b}} ->