Build universal wheels.
Use setuptools if present.
Don't mix unicode and bytes when loading schemas.

Get rid of stupid from __future__ import unicode_literals in places, which was
causing these to be unicode.
Drop support for 3.2
Update classifiers.
Enable branch coverage and show report on the command line.

Closes #137
Minor cleanup
Add 2.6
Maybe this satisfies Travis.
Or maybe this does.
Take 3.
Fix RTD links
Remove a lie.
Minor formatting.
Flake8
Add `relevance`, hopefully less confusing to directly use than by_relevance().
Minor cleanup.
Another leftover from unicode_literals
Remove indirection.
Add absolute path and absolute schema path.

Closes #120