use streams2 and make compatible with 0.8 and 0.10+
remove stream-spec

stream-spec author indicates that with streams2,
less testing should be needed and currently even plain
instances of streams2 don't seem to pass the specs.

It doesn't look like this will be updated for streams2
and currently is just causing failures, so is being
removed.
use streams2, stay compatible with node 0.8 and 0.10+
version 0.1.0