add forgotten validate params module

lib/validateParams.js

@@ -0,0 +1,19 @@
+'use strict';
+
+var conform = require('conform'),
+	_ = require('underscore');
+
+module.exports = function(params, schema, validateOptions) {
+	var defaultValidateOptions = {
+		additionalProperties: true,
+		failOnFirstError: true,
+		cast: true,
+		castSource: true,
+		applyDefaultValue: true
+	};
+
+	conform.validate(params, schema, _({}).extend(
+		defaultValidateOptions, validateOptions
+	));
+	return params;
+};