adopt actix-limitation crate (#229)

* import code from actix-limitation master branch

* fix compilation

* update legal info

* fix compile errors

* ignore failing tests

* remove futures dep

* add changelog

* update readme

* fix doc test example

actix-limitation/README.md

@@ -0,0 +1,51 @@
+# actix-limitation
+
+> Rate limiter using a fixed window counter for arbitrary keys, backed by Redis for Actix Web.  
+> Originally based on <https://github.com/fnichol/limitation>.
+
+[![crates.io](https://img.shields.io/crates/v/actix-limitation?label=latest)](https://crates.io/crates/actix-limitation)
+[![Documentation](https://docs.rs/actix-limitation/badge.svg?version=0.1.4)](https://docs.rs/actix-limitation/0.1.4)
+![Apache 2.0 or MIT licensed](https://img.shields.io/crates/l/actix-limitation)
+[![Dependency Status](https://deps.rs/crate/actix-limitation/0.1.4/status.svg)](https://deps.rs/crate/actix-limitation/0.1.4)
+
+## Examples
+
+```toml
+[dependencies]
+actix-limitation = "0.1.4"
+actix-web = "4"
+```
+
+```rust
+use std::time::Duration;
+use actix_web::{get, web, App, HttpServer, Responder};
+use actix_limitation::{Limiter, RateLimiter};
+
+#[get("/{id}/{name}")]
+async fn index(info: web::Path<(u32, String)>) -> impl Responder {
+    format!("Hello {}! id:{}", info.1, info.0)
+}
+
+#[actix_web::main]
+async fn main() -> std::io::Result<()> {
+    let limiter = web::Data::new(
+        Limiter::build("redis://127.0.0.1")
+            .cookie_name("session-id".to_owned())
+            .session_key("rate-api-id".to_owned())
+            .limit(5000)
+            .period(Duration::from_secs(3600)) // 60 minutes
+            .finish()
+            .expect("Can't build actix-limiter"),
+    );
+
+    HttpServer::new(move || {
+        App::new()
+            .wrap(RateLimiter)
+            .app_data(limiter.clone())
+            .service(index)
+    })
+    .bind("127.0.0.1:8080")?
+    .run()
+    .await
+}
+```