Clonable Stronghold Instance (#257)

* feat(interface): make stronghold clonable

* feat: updated tests

* feat(doc): add changes doc

.changes/clone-stronghold.md

@@ -0,0 +1,5 @@
+---
+"iota-stronghold": minor
+---
+
+- make stronghold interface clonable

client/src/interface.rs

@@ -41,6 +41,7 @@ use p2p::{
     Multiaddr, PeerId,
 };
 
+#[derive(Clone)]
 /// The main type for the Stronghold System.  Used as the entry point for the actor model.  Contains various pieces of
 /// metadata to interpret the data in the vault and store.
 pub struct Stronghold {

client/src/tests/interface_tests.rs

@@ -30,8 +30,11 @@ async fn test_stronghold() {
         .await
         .unwrap();
 
+    // clone it, and check for consistency
+    let stronghold2 = stronghold.clone();
+
     // Write at the first record of the vault using Some(0).  Also creates the new vault.
-    assert!(stronghold
+    assert!(stronghold2
         .write_to_vault(
             loc0.clone(),
             b"test".to_vec(),
@@ -42,6 +45,11 @@ async fn test_stronghold() {
         .is_ok());
 
     // read head.
+    let (p, _) = stronghold2.read_secret(client_path.clone(), loc0.clone()).await;
+
+    assert_eq!(std::str::from_utf8(&p.unwrap()), Ok("test"));
+
+    // read head from first reference
     let (p, _) = stronghold.read_secret(client_path.clone(), loc0.clone()).await;
 
     assert_eq!(std::str::from_utf8(&p.unwrap()), Ok("test"));