Add upgrade link to header.

Author: myronmarston

source/layouts/layout.slim

@@ -36,6 +36,7 @@ html.no-js lang="en"
         ul
           li= link_to 'About', '/about'
           li= link_to 'Documentation', '/documentation'
+          li= link_to 'Upgrade', '/upgrade'
           li= link_to 'Get Help', '/help'
           li= link_to 'Contributing', '/contributing'
     = yield

source/stylesheets/partials/_header.css.scss

@@ -6,7 +6,7 @@ header {
   height: 78px;
   h1 {
     background: url(image-path("logo-small.png")) left no-repeat;
-    @include span-columns(4);
+    @include span-columns(3);
     padding-left: 66px;
     padding-top: 12px;
     height: 100%;
@@ -18,7 +18,7 @@ header {
   }
   ul {
     text-align: right;
-    @include span-columns(8);
+    @include span-columns(9);
 
     li {
       display: inline-block;