message: Add no run to example
diff: //!
  //! This example configures a cluster consisting of a single node, and uses round-robin load balancing.
  //!
  -//! ```
  +//! ```no_run
  //! use cdrs_tokio::cluster::session::{TcpSessionBuilder, SessionBuilder};
  //! use cdrs_tokio::cluster::NodeTcpConfigBuilder;
  //! use cdrs_tokio::load_balancing::RoundRobinLoadBalancingStrategy;
  