Fix some more Javascript linting issues and discrepancies with upstream (#2209)

* Fix typo in flavours/glitch/features/video/index.js

* Fix various linting issues and discrepancies with upstream

app/javascript/flavours/glitch/components/display_name.jsx

@@ -14,6 +14,7 @@ export default class DisplayName extends React.PureComponent {
     localDomain: PropTypes.string,
     others: ImmutablePropTypes.list,
     handleClick: PropTypes.func,
+    onAccountClick: PropTypes.func,
   };
 
   handleMouseEnter = ({ currentTarget }) => {
@@ -61,6 +62,7 @@ export default class DisplayName extends React.PureComponent {
     if (others && others.size > 0) {
       displayName = others.take(2).map(a => (
         <a
+          key={a.get('id')}
           href={a.get('url')}
           target='_blank'
           onClick={(e) => onAccountClick(a.get('acct'), e)}