Add exists client error

app/error/type/client/exists.js

@@ -0,0 +1,25 @@
+'use strict';
+
+/**
+ * Dependencies
+ */
+let ClientError = require('../client');
+
+/**
+ * Constructor
+ */
+function ExistsError(message, data) {
+  message = message || 'Already exists';
+  ClientError.call(this, message, data, 400);
+}
+
+/**
+ * Extend prototype
+ */
+ExistsError.prototype = Object.create(ClientError.prototype);
+ExistsError.prototype.constructor = ExistsError;
+ExistsError.prototype.name = 'ExistsError';
+ExistsError.prototype.code = 'EXISTS';
+
+//Export
+module.exports = ExistsError;

app/error/type/client/not-found.js

@@ -8,9 +8,9 @@ let ClientError = require('../client');
 /**
  * Constructor
  */
-function NotFoundError(message) {
+function NotFoundError(message, data) {
   message = message || 'Resource not found';
-  ClientError.call(this, message, 404);
+  ClientError.call(this, message, data, 404);
 }
 
 /**