Add travis build status to readme

Author: nzakas

README

@@ -1,5 +1,6 @@
+[![build status](https://secure.travis-ci.org/nzakas/parser-lib.png)](http://travis-ci.org/nzakas/parser-lib)
 A collection of utilities, lexers, and parsers written in JavaScript.
 
 * src - contains the JavaScript source code.
 * build - contains the built files that are suitable for deployment.
-* templates - files used as part of the build system.
+* templates - files used as part of the build system.