Simplify usage of latte's 'connect' function from the 'context' module

Before there were 2 separate fn calls in the 'src/main.rs' module:

    let session = context::connect(conf).await?;
    let session = Context::new(session);

With this change we simplify it the way that we will do only one call:

    let session = context::connect(conf).await?;

src/context.rs

@@ -55,21 +55,22 @@ fn ssl_context(conf: &&ConnectionConf) -> Result<Option<SslContext>, CassError>
 }
 
 /// Configures connection to Cassandra.
-pub async fn connect(conf: &ConnectionConf) -> Result<scylla::Session, CassError> {
+pub async fn connect(conf: &ConnectionConf) -> Result<Context, CassError> {
     let profile = ExecutionProfile::builder()
         .consistency(conf.consistency.scylla_consistency())
         .request_timeout(Some(Duration::from_secs(60))) // no request timeout
         .build();
 
-    SessionBuilder::new()
+    let scylla_session = SessionBuilder::new()
         .known_nodes(&conf.addresses)
         .pool_size(PoolSize::PerShard(conf.count))
         .user(&conf.user, &conf.password)
         .ssl_context(ssl_context(&conf)?)
         .default_execution_profile_handle(profile.into_handle())
         .build()
         .await
-        .map_err(|e| CassError(CassErrorKind::FailedToConnect(conf.addresses.clone(), e)))
+        .map_err(|e| CassError(CassErrorKind::FailedToConnect(conf.addresses.clone(), e)))?;
+    Ok(Context::new(scylla_session))
 }
 
 pub struct ClusterInfo {

src/main.rs

@@ -109,7 +109,6 @@ fn find_workload(workload: &Path) -> PathBuf {
 async fn connect(conf: &ConnectionConf) -> Result<(Context, Option<ClusterInfo>)> {
     eprintln!("info: Connecting to {:?}... ", conf.addresses);
     let session = context::connect(conf).await?;
-    let session = Context::new(session);
     let cluster_info = session.cluster_info().await?;
     eprintln!(
         "info: Connected to {} running Cassandra version {}",