Updated async timeout message

There are now multiple ways to do async functions, and callbacks
are probably the least common in new code, so the message should
be more general rather than referring to callbacks.

src/core/QueueRunner.js

@@ -131,7 +131,7 @@ getJasmineRequireObj().QueueRunner = function(j$) {
       var timeoutInterval = queueableFn.timeout || j$.DEFAULT_TIMEOUT_INTERVAL;
       timeoutId = self.setTimeout(function() {
         var error = new Error(
-          'Timeout - Async callback was not invoked within ' +
+          'Timeout - Async function did not complete within ' +
             timeoutInterval +
             'ms ' +
             (queueableFn.timeout