Fix README node version typo.

README.md

@@ -25,11 +25,11 @@ These sample scripts require [Node.js](https://nodejs.org/en/) 6.x.x or greater.
 >
 > Then use nvm to install a recent version of [node.js](https://nodejs.org/en/):
 >
->   `nvm install v6.9.10`
+>   `nvm install v6.10.0`
 >
 > For future invocations now that Node.js is installed, you merely
 > need to tell your shell which version to use with
-> `nvm use v6.9.10`
+> `nvm use v6.10.0`
 
 1. git clone https://bitbucket.org/wikieducator/course.git
 2. cd course