runnable.js: fix async skip()

lib/runnable.js

@@ -347,7 +347,7 @@ Runnable.prototype.run = function(fn) {
       // halt execution.  the Runnable will be marked pending
       // by the previous call, and the uncaught handler will ignore
       // the failure.
-      throw new Pending('async skip; aborting execution');
+      // throw new Pending('async skip; aborting execution');
     };
 
     if (this.allowUncaught) {