Merge branch 'master' into gav-optional-storage

substrate/client/src/error.rs

@@ -76,6 +76,12 @@ error_chain! {
 			description("authority value state error"),
 			display("Current state of blockchain has invalid authority value for index {}", i),
 		}
+
+		/// Bad justification for header.
+		BadJustification(h: ::primitives::block::Id) {
+			description("bad justification for header"),
+			display("bad justification for header: {}", h),
+		}
 	}
 }