feat(gcs): add Google Cloud Storage support (#443)

* feat(gcs): add Google Cloud Storage support

Closes #436

* fix: honor configured protocol and finalization errors

* ci: remove TruffleHog checks

src/system/config_client.rs

@@ -532,6 +532,23 @@ mod tests {
         );
     }
 
+    #[test]
+    fn should_round_trip_gcs_as_default_protocol() {
+        let tmp_dir: TempDir = TempDir::new().ok().unwrap();
+        let (cfg_path, key_path): (PathBuf, PathBuf) = get_paths(tmp_dir.path());
+        let mut client = ConfigClient::new(cfg_path.as_path(), key_path.as_path())
+            .ok()
+            .unwrap();
+
+        client.set_default_protocol(FileTransferProtocol::GoogleCloudStorage);
+
+        assert_eq!(
+            client.get_default_protocol(),
+            FileTransferProtocol::GoogleCloudStorage
+        );
+        assert_eq!(client.config.user_interface.default_protocol, "GCS");
+    }
+
     #[test]
     fn test_system_config_show_hidden_files() {
         let tmp_dir: TempDir = TempDir::new().ok().unwrap();