Remove <h2> tag around service name in nav

The heading structure of most pages is incorrect (`<h2>` followed by
`<h1>`). The `<h1>` indicates the main purpose of the page, the service
name (currently the first `<h2>`) doesn't need to be a heading.

app/assets/stylesheets/components/navigation.scss

@@ -9,7 +9,7 @@
     margin: 0 0 10px;
     position: relative;
 
-    h2 {
+    &-name {
       @include bold-19;
       margin: 0 0 0 0;
     }