test: remove test-timers-first-fire

According to the documentation, "io.js makes no guarantees
about the exact timing of when the callback will fire"
(https://iojs.org/api/timers.html#timers_settimeout_callback_delay_arg),
hence this test is not necessary.

PR-URL: https://github.com/nodejs/node/pull/2458
Reviewed-By: Ben Noordhuis <ben@strongloop.com>
Reviewed-By: Alexis Campailla <alexis@janeasystems.com>

test/parallel/test-timers-first-fire.js

@@ -1,13 +0,0 @@
-'use strict';
-var common = require('../common');
-var assert = require('assert');
-
-var TIMEOUT = 50;
-var last = process.hrtime();
-setTimeout(function() {
-  var hr = process.hrtime(last);
-  var ms = (hr[0] * 1e3) + (hr[1] / 1e6);
-  var delta = ms - TIMEOUT;
-  console.log('timer fired in', delta);
-  assert.ok(delta > -0.5, 'Timer fired early');
-}, TIMEOUT);