added polyfill for travis

test/bind-polyfill.js

@@ -0,0 +1,27 @@
+if (!Function.prototype.bind) {
+  Function.prototype.bind = function(oThis) {
+    if (typeof this !== 'function') {
+      // closest thing possible to the ECMAScript 5
+      // internal IsCallable function
+      throw new TypeError('Function.prototype.bind - what is trying to be bound is not callable');
+    }
+
+    var aArgs   = Array.prototype.slice.call(arguments, 1),
+        fToBind = this,
+        fNOP    = function() {},
+        fBound  = function() {
+          return fToBind.apply(this instanceof fNOP
+                 ? this
+                 : oThis,
+                 aArgs.concat(Array.prototype.slice.call(arguments)));
+        };
+
+    if (this.prototype) {
+      // Function.prototype doesn't have a prototype property
+      fNOP.prototype = this.prototype; 
+    }
+    fBound.prototype = new fNOP();
+
+    return fBound;
+  };
+}

test/parents.coffee

@@ -1,3 +1,4 @@
+require './bind-polyfill.js'
 window.riot = require 'riot'
 parents = require '../lib/parents.js'
 simulant = require 'simulant'