v0.3 Launcher Improvements

• Fixed Process leak.
• User data dir support.

var userDataDir = Launcher.GetTemporaryDirectory();
var options = TestConstants.DefaultBrowserOptions();
options.UserDataDir = userDataDir;

var launcher = new Launcher();
var browser = await launcher.LaunchAsync(options, TestConstants.ChromiumRevision);

• Browser and Page now implements IDisposable.

var options = TestConstants.DefaultBrowserOptions();

using (var browser = await PuppeteerSharp.Puppeteer.LaunchAsync(options, TestConstants.ChromiumRevision))
using (var page = await browser.NewPageAsync())
{
    var response = await page.GoToAsync("https://www.google.com");
}