Bugfix/randomize cli db path (MystenLabs#367)

* use randomized db for cfg file based cli

fastpay/src/client.rs

@@ -14,11 +14,11 @@ use fastx_types::object::Object;
 use futures::stream::StreamExt;
 use std::{
     collections::{BTreeMap, HashSet},
-    env,
     path::PathBuf,
     time::{Duration, Instant},
 };
 use structopt::StructOpt;
+use tempfile::tempdir;
 use tokio::runtime::Runtime;
 use tracing::{subscriber::set_global_default, *};
 use tracing_subscriber::EnvFilter;
@@ -478,7 +478,7 @@ fn main() {
     let buffer_size = options.buffer_size;
     let client_db_path = options
         .db_path
-        .map_or(env::temp_dir().join("CLIENT_DB_0"), PathBuf::from);
+        .map_or(tempdir().unwrap().into_path(), PathBuf::from);
 
     let mut accounts_config =
         AccountsConfig::read_or_create(accounts_config_path).expect("Unable to read user accounts");
@@ -686,7 +686,7 @@ fn main() {
                 accounts_config.update_from_state(&client_state);
                 info!("Updating recipient's local balance");
 
-                let client2_db_path = env::temp_dir().join("CLIENT_DB_1");
+                let client2_db_path = tempdir().unwrap().into_path();
                 // TODO: client should manage multiple addresses instead of each addr having DBs
                 // https://github.com/MystenLabs/fastnft/issues/332
                 let mut recipient_client_state = make_client_state_and_try_sync(