handle node 0.10.0 compatibility edge case.

See explanation [here](https://github.com/joyent/node/blob/b26d346b57fc1964bc4b20d522a7bc2b68edb1be/deps/npm/node_modules/sha/node_modules/readable-stream/README.md#compatibility)

This resolves the issue I described on #6.  I would assume it also fixes @heneryville description as well.