Selenium: TestNG: Tests are not running in parallel

I have simple maven project with 3 class file. When I run my testng.xml file, tests are running in series.

I tried keeping parallel="classes", parallel="methods", parallel="tests" but no luck. Also tried by changing testng version from 6.9.0 to 7.0.0 but it didn't worked.

Expectations:

Tests should run in parallel

Actual:

Tests should running in series

Below is my project and all files.

Test Class: 1

public class TestOne {

private static WebDriver driver;
private static String baseURL;

@Test
public void launch() throws IOException {
    baseURL = "http://www.gmail.com";
    System.setProperty("webdriver.chrome.driver", "path");
    WebDriver driver = new ChromeDriver();
    driver.get(baseURL);
    driver.quit();
    }
}

Test Class: 2

public class TestTwo {

private static WebDriver driver;
private static String baseURL;

@Test
public void launch() throws IOException {
    baseURL = "http://www.gmail.com";
    System.setProperty("webdriver.chrome.driver", "path");
    WebDriver driver = new ChromeDriver();
    driver.get(baseURL);
    driver.quit();
    }
}

Test Class: 3

public class TestThree {

private static WebDriver driver;
private static String baseURL;

@Test
public void launch() throws IOException {
    baseURL = "http://www.gmail.com";
    System.setProperty("webdriver.chrome.driver", "path");
    WebDriver driver = new ChromeDriver();
    driver.get(baseURL);
    driver.quit();
    }
}

TestNG xml:

!DOCTYPE suite SYSTEM "http://testng.org/testng-1.0.dtd"

suite name="Test" parallel="tests" thread-count="3" data-provider-thread-count="5"<test name="Launch">
    <classes>
        <class name="test.demo.grid.TestOne" />
        <class name="test.demo.grid.TestTwo" />
        <class name="test.demo.grid.TestThree" />
    </classes>
</test>

Version:

selenium-java = 3.4.0

testng = 6.14.3

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Please let me know how can i fix it.

Thank you!