Should support connectionString containing password

[yelliver]

Instead of this:

    final client = await Client.connect('redis://myredis:8889');
    final commands = client.asCommands<String, String>();
    await commands.auth('password');

it is more elegant to do this:

    final client = await Client.connect('redis://username:password@myredis:8889');
    final commands = client.asCommands<String, String>();

[jcmellado]

Related: https://github.com/jcmellado/dartis/issues/23

[cjdenio]

This would definitely be helpful when working with Heroku Redis, where the password is passed to the client via a connection string.

Here's what I ended up using to get around it, if it helps anyone:

client = await Client.connect(Platform.environment["REDIS_URL"]);

var user = Uri.parse(Platform.environment["REDIS_URL"]).userInfo;
if (user != "") {
  await client.asCommands<String, String>().auth(user.split(":")[1]);
}

[kevinelliott]

I would love to see @cjdenio 's fix included.