bump some of the packages

gatsby-config.js

@@ -65,8 +65,5 @@ module.exports = {
         },
       },
     },
-    // this (optional) plugin enables Progressive Web App + Offline functionality
-    // To learn more, visit: https://gatsby.dev/offline
-    // `gatsby-plugin-offline`,
   ],
 };

src/gatsby-theme-material-ui-top-layout/theme.js

@@ -1,6 +1,6 @@
-import { createMuiTheme, responsiveFontSizes } from '@material-ui/core/styles';
+import { createTheme, responsiveFontSizes } from '@material-ui/core/styles';
 
-const theme = createMuiTheme({
+const theme = createTheme({
   palette: {
     type: 'dark',
   },