fix syntax error

lib/api/dash.js

@@ -1,7 +1,7 @@
 var util = require('util');
 var v8type = require('v8type');
 
-var validate_dashboard(dashboard){
+var validate_dashboard = function(dashboard){
     if(!v8type.of(dashboard, v8type.OBJECT)){
 	throw new Error('`dashboard` parameter must be an object');
     }