move ribbon example to the end

src/examples.jl

@@ -152,23 +152,6 @@ plot(y, line = (5, styles), label = map(string,styles), legendtitle = "linestyle
              end)]
 ),
 
-PlotExample("Ribbons",
-    """
-    Ribbons can be added to lines via the `ribbon` keyword;
-    you can pass a tuple of arrays (upper and lower bounds),
-    a single Array (for symmetric ribbons), a Function, or a number.
-    """,
-    [:(begin
-        plot(
-            plot(0:10; ribbon = (LinRange(0, 2, 10), LinRange(0, 1, 10))),
-            plot(0:10; ribbon = 0:0.5:5),
-            plot(0:10; ribbon = sqrt),
-            plot(0:10; ribbon = 1),
-        )
-    end)
-    ]
-),
-
 PlotExample("Marker types",
     "",
     [:(begin
@@ -471,6 +454,23 @@ see: http://stackoverflow.com/a/37732384/5075246
     end)]
 ),
 
+PlotExample("Ribbons",
+    """
+    Ribbons can be added to lines via the `ribbon` keyword;
+    you can pass a tuple of arrays (upper and lower bounds),
+    a single Array (for symmetric ribbons), a Function, or a number.
+    """,
+    [:(begin
+        plot(
+            plot(0:10; ribbon = (LinRange(0, 2, 10), LinRange(0, 1, 10))),
+            plot(0:10; ribbon = 0:0.5:5),
+            plot(0:10; ribbon = sqrt),
+            plot(0:10; ribbon = 1),
+        )
+    end)
+    ]
+),
+
 ]
 
 # Some constants for PlotDocs and PlotReferenceImages