Show which dependencies are optional

Author: bluss

app/styles/app.scss

@@ -146,6 +146,10 @@ span.small {
     }
 }
 
+.optional {
+    font-size: 80%;
+}
+
 .yanked {
     font-size: 80%;
     color: rgb(166, 0, 0)

app/templates/crate/version.hbs

@@ -137,6 +137,9 @@
     <ul>
       {{#each currentDependencies as |dep|}}
         {{link-to-dep dep=dep}}
+        {{#if dep.optional}}
+            <span class='optional'>optional</span>
+        {{/if}}
       {{else}}
           <li>None</li>
       {{/each}}