message: updated README to latest changes
diff: @@ -34,7 +34,7 @@ To use password authenticator, just include the one implemented in
  ```rust
  use cdrs::client::CDRS;
  use cdrs::authenticators::PasswordAuthenticator;
  -use cdrs::transport::Transport;
  +use cdrs::transport::TransportPlain;
  ```
  After that you can create a new instance of `CDRS` and establish new connection:
  @@ -42,7 +42,7 @@ After that you can create a new instance of `CDRS` and establish new connection:
  ```rust
  let authenticator = PasswordAuthenticator::new("user", "pass");
  let addr = "127.0.0.1:9042";
  -let tcp_transport = Transport::new(addr).unwrap();
  +let tcp_transport = TransportPlain::new(addr).unwrap();
  // pass authenticator and transport into CDRS' constructor
  let client = CDRS::new(tcp_transport, authenticator);
  @@ -71,7 +71,7 @@ features = ["ssl"]
  ```rust
  use cdrs::client::CDRS;
  use cdrs::authenticators::PasswordAuthenticator;
  -use cdrs::transport_ssl::Transport;
  +use cdrs::transport::TransportTls;
  use openssl::ssl::{SslConnectorBuilder, SslMethod};
  use std::path::Path;
  ```
  @@ -88,7 +88,7 @@ let mut ssl_connector_builder = SslConnectorBuilder::new(SslMethod::tls()).unwra
  ssl_connector_builder.builder_mut().set_ca_file(path).unwrap();
  let connector = ssl_connector_builder.build();
  -let ssl_transport = Transport::new(addr, &connector).unwrap();
  +let ssl_transport = TransportTls::new(addr, &connector).unwrap();
  // pass authenticator and SSL transport into CDRS' constructor
  let client = CDRS::new(ssl_transport, authenticator);
  @@ -105,7 +105,7 @@ use cdrs::connection_manager::ConnectionManager;
  let config = r2d2::Config::builder()
  .pool_size(15)
  .build();
  -let transport = Transport::new(ADDR).unwrap();
  +let transport = TransportPlain::new(ADDR).unwrap();
  let authenticator = PasswordAuthenticator::new(USER, PASS);
  let manager = ConnectionManager::new(transport, authenticator, Compression::None);
  