Python3 support

[chrysn]

Please consider adding support for Python3 to hydra-py.

It seems not to be many changes; the branch at https://github.com/andrejsab/hydra-py/ lists the first steps. (I had to drop the httplib2 workaround linebreaks in DEFAULT_REQUEST_HEADERS because those caused requests like this:

GET /dbpedia2014 HTTP/1.1
Host: data.linkeddatafragments.org
accept: application/ld+json, application/n-quads;q=0.9,
GET /dbpedia2014 HTTP/1.1
Host: data.linkeddatafragments.org
accept: application/ld+json, application/n-quads;q=0.9,
 application/turtle;q=0.8, application/n-triples;q=0.7,
 application/rdf+xml;q=0.6, text/html;q=0.5, */*;q=0.1
accept-encoding: gzip, deflate
user-agent: hydra-py-v0.1

; looks like a workaround that triggers another bug in more recent versions).

There are some more places that need fixing in the string handling area, like string literals becoming encoded with as b"x" in the query parameter; I'll update the issue when I find where those came from exactly.

Will you aim for 2+3 compatibility, or switch right away to 3?

[pchampin]

Thanks for this comment, and sorry for the late reply.

I would rather maintain 2+3 compatibility. I'll have a look at your fork soon.