fix for node8

lib/encoding/bufferreader.js

@@ -17,8 +17,12 @@ var BufferReader = function BufferReader(buf) {
       buf: buf
     });
   } else if (_.isString(buf)) {
+    var b = new Buffer(buf, 'hex');
+    if (b.length * 2 != buf.length) 
+      throw new TypeError('Invalid hex string');
+
     this.set({
-      buf: new Buffer(buf, 'hex'),
+      buf: b,
     });
   } else if (_.isObject(buf)) {
     var obj = buf;