[ROADMAP] Update the roadmap

ROADMAP.md

@@ -1,3 +1,13 @@
 # Roadmap
 
 The roadmap is a living document, and it is likely that priorities will change, but the list below should give some indication of our plans for the next major release, and for the future.
+
+Our priorities:
+1. **Material Design**. The Google Design team has recently released a new iteration on the Material Design specification, it’s focused on *themability*. This is great news! We will do our best to be up to date. It also confirms that heavily investing in customizability for v1 was a good call. We will continue our efforts.
+1. **More utils**. We want to work on new utility components: Spacing, Display, Color, etc.
+1. **Performance**. We can’t optimize something we can’t measure, and we don’t currently have a CI performance benchmark, so we will need to build one and start investigating bottlenecks.
+1. **Learning materials**. The quality of the documentation is equally as important as the quality of the implementation, and while the reference documentation is comprehensive, we could author a learning tutorial like Next.js has done, or an egghead.io course.
+Themes. We want to provide common layouts example to make getting started even easier. We also plan on adding more premium themes.
+1. **Documentation**. We want to translate the documentation into Chinese and more languages. Any help is welcomed!
+1. **Bundle size**. The library needs to be as small as possible, so we need to work on solutions to further reduce the bundle size, for instance, supporting Preact or Nerv can help.
+1. **Type checking**. We will continue to improve the TypeScript and maybe the Flow coverage of the library.

docs/src/pages/demos/snackbars/CustomizedSnackbars.js

@@ -2,9 +2,9 @@ import React from 'react';
 import PropTypes from 'prop-types';
 import classNames from 'classnames';
 import Button from '@material-ui/core/Button';
-import CheckIcon from '@material-ui/icons/Check';
-import ErrorOutlineIcon from '@material-ui/icons/ErrorOutline';
-import InfoIcon from '@material-ui/icons/InfoOutline';
+import CheckCircleIcon from '@material-ui/icons/CheckCircle';
+import ErrorIcon from '@material-ui/icons/Error';
+import InfoIcon from '@material-ui/icons/Info';
 import CloseIcon from '@material-ui/icons/Close';
 import green from '@material-ui/core/colors/green';
 import amber from '@material-ui/core/colors/amber';
@@ -15,9 +15,9 @@ import WarningIcon from '@material-ui/icons/Warning';
 import { withStyles } from '@material-ui/core/styles';
 
 const variantIcon = {
-  success: CheckIcon,
+  success: CheckCircleIcon,
   warning: WarningIcon,
-  error: ErrorOutlineIcon,
+  error: ErrorIcon,
   info: InfoIcon,
 };
 
@@ -38,6 +38,7 @@ const styles1 = theme => ({
     fontSize: 20,
   },
   iconVariant: {
+    opacity: 0.9,
     marginRight: theme.spacing.unit,
   },
   message: {