use package version in default agent string

lib/reader.js

@@ -17,7 +17,7 @@ try {
 
 var m3u8 = require('./m3u8');
 
-var DEFAULT_AGENT = util.format('hls-tools/v%s (http://github.com/kanongil/node-hls-tools) node.js/%s', '0.0.0', process.version);
+var DEFAULT_AGENT = util.format('hls-tools/v%s (http://github.com/kanongil/node-hls-tools) node.js/%s', require('../package').version, process.version);
 
 module.exports = hlsreader;
 hlsreader.HlsStreamReader = HlsStreamReader;