add more known styles

Signed-off-by: Juan Pablo Garcia Ripa <sarabadu@gmail.com>

packages/eslint-plugin/src/no-top-level-material-ui-4-imports.test.ts

@@ -93,6 +93,8 @@ import SvgIcon, { SvgIconProps } from '@material-ui/core/SvgIcon';`,
                   ThemeProvider,
                   WithStyles,
                   Tooltip as MaterialTooltip,
+                  alpha,
+                  easing
                 } from '@material-ui/core';`,
       errors: [{ messageId: 'topLevelImport' }],
       output: `import Box from '@material-ui/core/Box';
@@ -101,7 +103,7 @@ import DialogContent from '@material-ui/core/DialogContent';
 import DialogTitle from '@material-ui/core/DialogTitle';
 import Grid from '@material-ui/core/Grid';
 import MaterialTooltip from '@material-ui/core/Tooltip';
-import { makeStyles, ThemeProvider, WithStyles } from '@material-ui/core/styles';`,
+import { makeStyles, ThemeProvider, WithStyles, alpha, easing } from '@material-ui/core/styles';`,
     },
     {
       code: `import { Box, Button, makeStyles } from '@material-ui/core';`,
@@ -111,11 +113,11 @@ import Button from '@material-ui/core/Button';
 import { makeStyles } from '@material-ui/core/styles';`,
     },
     {
-      code: `import { Paper, Typography, styled, withStyles } from '@material-ui/core';`,
+      code: `import { Paper, Typography, styled, withStyles, alpha, duration} from '@material-ui/core';`,
       errors: [{ messageId: 'topLevelImport' }],
       output: `import Paper from '@material-ui/core/Paper';
 import Typography from '@material-ui/core/Typography';
-import { styled, withStyles } from '@material-ui/core/styles';`,
+import { styled, withStyles, alpha, duration } from '@material-ui/core/styles';`,
     },
     {
       code: `import { styled } from '@material-ui/core';`,