chore: Update roadmap to reflect MDCW (#237)

Author: lynnmercier

ROADMAP.md

@@ -2,21 +2,34 @@
 We release a new version of MDC React every 2 weeks. We try and keep MDC React within one version of MDC Web. This roadmap is based of the [MDC Web roadmap](https://github.com/material-components/material-components-web/blob/master/ROADMAP.md), but specific to MDC React.
 
 ## Current Release
-### 0.4.0 - June 2018
-- Depend on MDC Web 0.37.x
+### 0.4.x - June 2018
+- Depend on MDC Web 0.38.x
 - New extended FAB
+- New select
 
 ## Upcoming Releases
 
-### 0.5.0 - August 2018
-- Depend on MDC Web 0.38.x
-- New select
+### 0.5.x - September 2018
+- Depend on MDC Web 0.39.x
 - New tabs
 - New switch
-
-### 0.6.0 - September 2018
-- Depend on MDC Web 0.39.x
 - New chips
+- New icon button
+
+### 0.6.x - October 2018
+- Depend on MDC Web 0.40.x
+- New list
 - New navigation drawer
 - New menu
-- New icon button
+- New checkbox
+- New dialog
+
+### 0.7.x - November 2018
+- Depend on MDC Web 0.41.x
+- New select (drop down menu attached to a text field)
+- New side sheet
+- New radio
+
+### 0.8.x - December 2018
+- Depend on MDC Web 0.42.x
+- Prefix and suffix support in Text Field