[SpeedDial] Remove dead code from test (#12545)

packages/material-ui-lab/src/SpeedDial/SpeedDial.test.js

@@ -1,15 +1,14 @@
 import React from 'react';
 import { assert } from 'chai';
 import { spy } from 'sinon';
-import { createMount, createShallow, getClasses } from '@material-ui/core/test-utils';
+import { createShallow, getClasses } from '@material-ui/core/test-utils';
 import Icon from '@material-ui/core/Icon';
 import Button from '@material-ui/core/Button';
 import SpeedDial from './SpeedDial';
 import SpeedDialAction from '../SpeedDialAction';
 
 describe('<SpeedDial />', () => {
   let shallow;
-  let mount;
   let classes;
   const icon = <Icon>font_icon</Icon>;
   const defaultProps = {
@@ -19,18 +18,13 @@ describe('<SpeedDial />', () => {
 
   before(() => {
     shallow = createShallow({ dive: true });
-    mount = createMount();
     classes = getClasses(
       <SpeedDial {...defaultProps} icon={icon}>
         <div />
       </SpeedDial>,
     );
   });
 
-  after(() => {
-    mount.cleanUp();
-  });
-
   it('should render a Fade transition', () => {
     const wrapper = shallow(
       <SpeedDial {...defaultProps} icon={icon}>