Added 16.3 changelog to version links

Author: bvaughn

content/versions.yml

@@ -1,3 +1,5 @@
+- title: '16.3.1'
+  changelog: https://github.com/facebook/react/blob/master/CHANGELOG.md#1631-april-3-2018
 - title: '16.2.0'
   path: /version/16.2
   url: https://5abc31d8be40f1556f06c4be--reactjs.netlify.com

plugins/gatsby-transformer-versions-yaml/gatsby-node.js

@@ -20,7 +20,7 @@ exports.onPostBuild = async ({store}) => {
 
   // versions.yml structure is [{path: string, url: string, ...}, ...]
   createRedirects(
-    versions.map(version => ({
+    versions.filter(version => version.path && version.url).map(version => ({
       fromPath: version.path,
       toPath: version.url,
     })),

src/pages/versions.js

@@ -39,11 +39,13 @@ const Versions = () => (
                     Changelog
                   </a>
                 </li>
-                <li>
-                  <a href={version.path} rel="nofollow">
-                    Documentation
-                  </a>
-                </li>
+                {version.path && (
+                  <li>
+                    <a href={version.path} rel="nofollow">
+                      Documentation
+                    </a>
+                  </li>
+                )}
               </ul>
             </div>
           ))}