Merge pull request bitcoin#329 from ralphtheninja/travis-badge

Add travis build badge to README

Author: cmumford

README.md

@@ -1,5 +1,7 @@
 **LevelDB is a fast key-value storage library written at Google that provides an ordered mapping from string keys to string values.**
 
+[![Build Status](https://travis-ci.org/google/leveldb.svg?branch=master)](https://travis-ci.org/google/leveldb)
+
 Authors: Sanjay Ghemawat (sanjay@google.com) and Jeff Dean (jeff@google.com)
 
 # Features