Fixing clippy warnings

util/src/trie/journal.rs

@@ -14,6 +14,7 @@
 // You should have received a copy of the GNU General Public License
 // along with Parity.  If not, see <http://www.gnu.org/licenses/>.
 
+use std::default::Default;
 use sha3::*;
 use hash::H256;
 use bytes::*;
@@ -39,6 +40,12 @@ pub struct Score {
 #[derive(Debug)]
 pub struct Journal (Vec<Operation>);
 
+impl Default for Journal {
+	fn default() -> Self {
+		Journal::new()
+	}
+}
+
 impl Journal {
 	/// Create a new, empty, object.
 	pub fn new() -> Journal { Journal(vec![]) }