improvement: flow coverage

src/components/Sidebar/Copyright/Copyright.js

@@ -1,7 +1,12 @@
+// @flow
 import React from 'react';
 import styles from './Copyright.module.scss';
 
-const Copyright = ({ copyright }) => (
+type Props = {
+  copyright: string
+};
+
+const Copyright = ({ copyright }: Props) => (
   <div className={styles['copyright']}>
     {copyright}
   </div>

src/components/Sidebar/Copyright/Copyright.test.js

@@ -1,3 +1,4 @@
+// @flow
 import React from 'react';
 import renderer from 'react-test-renderer';
 import Copyright from './Copyright';

src/components/Sidebar/Copyright/index.js

@@ -1 +1,2 @@
+// @flow
 export { default } from './Copyright';