fails to decompress files created with `bgzip`

[rbuels]

Some files created with bgzip cannot be decompressed, or at least not with the same options as node's native zlib.

[rbuels]

#35 demonstrates this. The test passes if you change the zlib import to native.

[rbuels]

Interestingly, it's possible to decompress these files using pako directly, nodeca/pako#146 demonstrates a way that works.