build: remove examples/simple.rs

When `cargo test` is executed,
all examples are built by default
to ensure that they can be compiled.

This is a documented and expected behaviour,
even though it was previously reported as a bug:
<https://github.com/rust-lang/cargo/issues/6675>

In particular, `examples/simple.rs` is built into
a 67M binary `target/debug/examples/simple`.
This is unnecessary to do so every time
you change a line in the `deltachat` crate
and want to rerun the tests.

Workaround is to run `cargo test --tests`,
but it is easy to forget and is not discoverable
unless you read the "Target Selection" section of `cargo help test`.

We have a maintained example at https://github.com/deltachat-bot/echo,
so there is no need for an example in the core repository.

Cargo.toml

@@ -118,11 +118,6 @@ members = [
   "format-flowed",
 ]
 
-[[example]]
-name = "simple"
-path = "examples/simple.rs"
-
-
 [[bench]]
 name = "create_account"
 harness = false

examples/simple.rs

@@ -1,100 +0,0 @@
-use deltachat::chat::{self, ChatId};
-use deltachat::chatlist::*;
-use deltachat::config;
-use deltachat::contact::*;
-use deltachat::context::*;
-use deltachat::message::Message;
-use deltachat::stock_str::StockStrings;
-use deltachat::{EventType, Events};
-use tempfile::tempdir;
-
-fn cb(event: EventType) {
-    match event {
-        EventType::ConfigureProgress { progress, .. } => {
-            log::info!("progress: {}", progress);
-        }
-        EventType::Info(msg) => {
-            log::info!("{}", msg);
-        }
-        EventType::Warning(msg) => {
-            log::warn!("{}", msg);
-        }
-        EventType::Error(msg) => {
-            log::error!("{}", msg);
-        }
-        event => {
-            log::info!("{:?}", event);
-        }
-    }
-}
-
-/// Run with `RUST_LOG=simple=info cargo run --release --example simple -- email pw`.
-#[tokio::main]
-async fn main() {
-    pretty_env_logger::try_init_timed().ok();
-
-    let dir = tempdir().unwrap();
-    let dbfile = dir.path().join("db.sqlite");
-    log::info!("creating database {:?}", dbfile);
-    let ctx = Context::new(&dbfile, 0, Events::new(), StockStrings::new())
-        .await
-        .expect("Failed to create context");
-    let info = ctx.get_info().await;
-    log::info!("info: {:#?}", info);
-
-    let events = ctx.get_event_emitter();
-    let events_spawn = tokio::task::spawn(async move {
-        while let Some(event) = events.recv().await {
-            cb(event.typ);
-        }
-    });
-
-    log::info!("configuring");
-    let args = std::env::args().collect::<Vec<String>>();
-    assert_eq!(args.len(), 3, "requires email password");
-    let email = args[1].clone();
-    let pw = args[2].clone();
-    ctx.set_config(config::Config::Addr, Some(&email))
-        .await
-        .unwrap();
-    ctx.set_config(config::Config::MailPw, Some(&pw))
-        .await
-        .unwrap();
-
-    ctx.configure().await.unwrap();
-
-    log::info!("------ RUN ------");
-    ctx.start_io().await;
-    log::info!("--- SENDING A MESSAGE ---");
-
-    let contact_id = Contact::create(&ctx, "dignifiedquire", "dignifiedquire@gmail.com")
-        .await
-        .unwrap();
-    let chat_id = ChatId::create_for_contact(&ctx, contact_id).await.unwrap();
-
-    for i in 0..1 {
-        log::info!("sending message {}", i);
-        chat::send_text_msg(&ctx, chat_id, format!("Hi, here is my {i}nth message!"))
-            .await
-            .unwrap();
-    }
-
-    // wait for the message to be sent out
-    tokio::time::sleep(std::time::Duration::from_secs(1)).await;
-
-    log::info!("fetching chats..");
-    let chats = Chatlist::try_load(&ctx, 0, None, None).await.unwrap();
-
-    for i in 0..chats.len() {
-        let msg = Message::load_from_db(&ctx, chats.get_msg_id(i).unwrap().unwrap())
-            .await
-            .unwrap();
-        log::info!("[{}] msg: {:?}", i, msg);
-    }
-
-    log::info!("stopping");
-    ctx.stop_io().await;
-    log::info!("closing");
-    drop(ctx);
-    events_spawn.await.unwrap();
-}