add user signup through loopback

server/datasources.local.js

@@ -1,6 +1,19 @@
+var secrets = require('../config/secrets');
+
 module.exports = {
   db: {
     connector: 'mongodb',
     url: process.env.MONGOHQ_URL
+  },
+  mail: {
+    connector: 'mail',
+    transports: [{
+      type: 'smtp',
+      service: 'Mandrill',
+      auth: {
+        user: secrets.mandrill.user,
+        pass: secrets.mandrill.password
+      }
+    }]
   }
 };