fix util.isBuffer to work in browserify 3.x

Author: feross

support/isBufferBrowser.js

@@ -2,6 +2,5 @@ module.exports = function isBuffer(arg) {
   return arg && typeof arg === 'object'
     && typeof arg.copy === 'function'
     && typeof arg.fill === 'function'
-    && typeof arg.binarySlice === 'function'
-    ;
-}
+    && typeof arg.readUInt8 === 'function';
+}