adjusts some py3 incompat and fixes vizier bug
Merge pull request #197 from jdnc/fix-py3-encodes

Astroquery compatibility with PY3...
lon -> lon % 360
BAD fixes to get tests to pass.  For whatever reason, pytest claims that
commons.parse_radius(9.8*u.kg) does *NOT* raise an exception, but from
every test I've performed, it DOES.