update examples

Author: sunli829

tide/dataloader-postgres/Cargo.toml

@@ -8,7 +8,6 @@ edition = "2018"
 async-graphql = { path = "../../..", features = ["dataloader"] }
 async-graphql-tide = { path = "../../../integrations/tide" }
 async-std = "1.9.0"
-async-trait = "0.1.42"
 itertools = "0.10.0"
 sqlx = { version = "0.7.2", features = [
     "runtime-async-std-rustls",

tide/dataloader-postgres/src/main.rs

@@ -7,7 +7,6 @@ use async_graphql::{
     Context, EmptyMutation, EmptySubscription, FieldError, Object, Result, Schema, SimpleObject,
 };
 use async_std::task;
-use async_trait::async_trait;
 use sqlx::PgPool;
 use tide::{http::mime, Body, Response, StatusCode};
 
@@ -26,7 +25,6 @@ impl BookLoader {
     }
 }
 
-#[async_trait]
 impl Loader<i32> for BookLoader {
     type Value = Book;
     type Error = FieldError;

tide/dataloader/Cargo.toml

@@ -10,7 +10,6 @@ async-graphql-tide = { path = "../../../integrations/tide" }
 tide = "0.16"
 async-std = "1.9.0"
 sqlx = { version = "0.7.2", features = ["sqlite", "runtime-async-std-rustls"] }
-async-trait = "0.1.30"
 itertools = "0.9.0"
 
 [dev-dependencies]

tide/dataloader/src/main.rs

@@ -7,7 +7,6 @@ use async_graphql::{
     Context, EmptyMutation, EmptySubscription, FieldError, Object, Result, Schema, SimpleObject,
 };
 use async_std::task;
-use async_trait::async_trait;
 use itertools::Itertools;
 use sqlx::{Pool, Sqlite};
 use tide::{http::mime, Body, Response, StatusCode};
@@ -27,7 +26,6 @@ impl BookLoader {
     }
 }
 
-#[async_trait]
 impl Loader<i32> for BookLoader {
     type Value = Book;
     type Error = FieldError;