Add gravatar support to derby-auth


Add Gravatar support to derby-auth.

First follow the steps for getting started with derby-auth.

Next require the module in server/index.js:

var gravatar = require('derby-auth-gravatar');

Add gravatar after derby-auth middleware:

// derby-auth middleware 
.use(auth.middleware(strategies, options)) 
// gravatar middleware 

A user's gravatar data is stored in "users.*.auth.local.gravatar". Each gravatar object contains a hash property that can be used to generate a gravatar image url

<img alt="" src="{{_user.auth.local.gravatar.hash}}">

If a user has a profile then their profile data will also be stored in the gravatar object.

<pre class="displayName">{{}}</pre>

*Note: For whatever reason, secondary gravatar accounts do not return profile data.