Fix time zone issue.

package org.skywalking.apm.collector.core.util;

import java.util.TimeZone;

import org.junit.After;

import org.junit.Assert;

import org.junit.Before;

import org.junit.Test;

/**

 * @author wu-sheng

 */

public class TimeBucketUtilsTest {

    @Before

    public void setup() {

        TimeZone.setDefault(TimeZone.getTimeZone("Asia/Shanghai"));

    }

    @After

    public void teardown() {

    }

    @Test

    public void testGetInfoFromATimestamp() {

        long timeMillis = 1509521745220L;