Migrating to 2.0.0

HttpServer::start() renamed to HttpServer::run(). It also possible to .await on run method result, in that case it awaits server exit.
App::register_data() renamed to App::app_data() and accepts any type T: 'static. Stored data is available via HttpRequest::app_data() method at runtime.
Extractor configuration must be registered with App::app_data() instead of App::data()
Sync handlers has been removed. .to_async() method has been renamed to .to() replace fn with async fn to convert sync handler to async
actix_http_test::TestServer moved to actix_web::test module. To start test server use test::start() or test_start_with_config() methods
ResponseError trait has been refactored. ResponseError::error_response() renders http response.

Feature rust-tls renamed to rustls

instead of

actix-web = { version = "2.0.0", features = ["rust-tls"] }

use

actix-web = { version = "2.0.0", features = ["rustls"] }

Feature ssl renamed to openssl

instead of

actix-web = { version = "2.0.0", features = ["ssl"] }

use

actix-web = { version = "2.0.0", features = ["openssl"] }

Cors builder now requires that you call .finish() to construct the middleware