Merge branch 'system-notes-fade' into 'master'

Fade out should be white instead of gray

Currently, you can see the hard edge of the fade out because it's a light shade of gray rather than white.   
Before:   
![Screen_Shot_2016-12-07_at_12.36.10_PM](/uploads/c8fd2c6ba1742d1260614fd4c9cb29c9/Screen_Shot_2016-12-07_at_12.36.10_PM.png)
After:   
![Screen_Shot_2016-12-07_at_12.35.53_PM](/uploads/52b51e4a825658a0c440e0f1fb86a31c/Screen_Shot_2016-12-07_at_12.35.53_PM.png)
cc @nmrony

See merge request !7979

app/assets/stylesheets/pages/notes.scss

@@ -124,7 +124,7 @@ ul.notes {
             position: absolute;
             left: 0;
             bottom: 0;
-            background: linear-gradient(rgba($gray-light, 0.1) -100px, $white-light 100%);
+            background: linear-gradient(rgba($white-light, 0.1) -100px, $white-light 100%);
           }
 
           &.hide-shade {