fix: Unicode resp.body not encoded to a byte string

Required per PEP 333.

Fixes #51
Merge remote-tracking branch 'upstream/master' into Issue_51
feat(Response): Added data member

resp.body decodes strings now, which slows it down a bit. Use
resp.data, instead, for byte strings.
style(API): Removed unused import, fixed spacing
refactor(Request): Rename Request.body to Request.stream

BREAKING CHANGE: req.body renamed to req.stream, since it really is a
stream, and the new name mirrors resp.stream.

Fixes #43
Merge pull request #60 from kgriffs/Issue_51

Issue 51
Merge remote-tracking branch 'upstream/master' into Issue-43
Merge pull request #61 from kgriffs/Issue-43

Issue #43