Fix typo in README.md

Oops.

README.md

@@ -1,7 +1,7 @@
 # striptags [![Build Status](https://travis-ci.org/ericnorris/striptags.svg)](https://travis-ci.org/ericnorris/striptags)
 An implementation of PHP's [strip_tags](http://www.php.net/manual/en/function.strip-tags.php) in Node.js.
 
-**Note:** `v3+` targets ES6, and is therefore incompatible with the maaster branch of `uglifyjs`. You can either:
+**Note:** `v3+` targets ES6, and is therefore incompatible with the master branch of `uglifyjs`. You can either:
 - use `babili`, which supports ES6
 - use the `harmony` branch of `uglifyjs`
 - stick with the [2.x.x](https://github.com/ericnorris/striptags/tree/v2.x.x) branch