Unable use send_file, "Invalid scheme for Http"

[Masterchef365]

Having trouble getting files to send using send_file. Commit hash: 245f573
Example code:

// Log in to Discord using a bot token from the environment
let discord = Discord::from_bot_token(&env::var("DISCORD_TOKEN").expect("Expected token"))
    .expect("login failed");

// Establish and use a websocket connection
let (mut connection, _) = discord.connect().expect("connect failed");
println!("Ready.");
loop {
    match connection.recv_event() {
        Ok(Event::MessageCreate(message)) => {
            println!("{} says: {}", message.author.name, message.content);
            if message.content == "!test" {
                discord.send_file(
                    message.channel_id,
                    "This is a reply to the test.",
                    "This is a test text file".as_bytes(),
                    "test.txt",
                ).expect("Failed to send file");
            }
        }
        Ok(_) => {}
        Err(discord::Error::Closed(code, body)) => {
            println!("Gateway closed on us with code {:?}: {}", code, body);
            break;
        }
        Err(err) => println!("Receive error: {:?}", err),
    }
}

When I DM the bot !test, I get the following:

thread 'main' panicked at 'Failed to send file: Hyper(Io(Custom { kind: InvalidInput, error: "Invalid scheme for Http" }))'

Which suggests to me that TLS isn't being used... But I'm not sure. I tried to find where the hyper Client was being referenced, but didn't have much time. I'll try stepping through the code later tonight to see where the problem might be (and perhaps submit a PR if I find a fix) but I wanted to create an issue first.

[chxry]

Have you managed to fix this issue. I have the same error using send_file