Fix support for updated bops module

Bops support added with #4 also tries to read uint8 bytes from `parseHead()` results but `parseHead()` returns an array instead of a buffer. This breaks new bops where the method is called directly instead of binding.

btw, the version of this module that is currently on npm throws on decoding any array key. git master is ok because the bops dependency is set to 0.0.6 here.