Update to Emotion 11

Summary: Per title

Reviewed By: passy

Differential Revision: D24994086

fbshipit-source-id: 84d83638ec518a39ea2d80f56b8c794c8b86a9d4

desktop/app/src/index.tsx

@@ -8,7 +8,7 @@
  */
 
 export {default as styled} from '@emotion/styled';
-export {keyframes} from 'emotion';
+export {keyframes} from '@emotion/css';
 export {produce} from 'immer';
 
 export * from './ui/index';