Fix/refactor tests

src/modules/record_sheet.js

@@ -195,3 +195,8 @@ export function start(startLoc, units) {
   Observable.subscribe('select', select);
   Observable.subscribe('endmove', endMove);
 }
+
+export function stop() {
+  Observable.unsubscribe('select', select);
+  Observable.unsubscribe('endmove', endMove);
+}