LT-251: Making series switch behave like demonstrated in the design video

Packages/design/styles/mixins.styl

@@ -5,6 +5,13 @@ transition(t)
   -o-transition: t
   -moz-transition: t
 
+transition-delay(d)
+  transition-delay: d
+  -webkit-transition-delay: d
+  -ms-transition-delay: d
+  -o-transition-delay: d
+  -moz-transition-delay: d
+
 transform(t)
   transform: t
   -webkit-transform: t