Cache Object#hasOwnProperty in case clients break it as part of tests

Obviates inspect-js/object-inspect#2.

Author: ljharb

lib/results.js

@@ -3,6 +3,7 @@ var inherits = require('inherits');
 var through = require('through');
 var resumer = require('resumer');
 var inspect = require('object-inspect');
+var hasOwn = Object.prototype.hasOwnProperty;
 var nextTick = typeof setImmediate !== 'undefined'
     ? setImmediate
     : process.nextTick
@@ -185,5 +186,5 @@ function getNextTest (results) {
 }
 
 function has (obj, prop) {
-    return Object.prototype.hasOwnProperty.call(obj, prop);
+    return hasOwn.call(obj, prop);
 }