Don't use hardcoded temp file in test_utils
Merge pull request #387 from sargas/cleanup-temp-file

Don't use hardcoded temp file in test_utils
try importing astropy's six; failure -> system six
Merge pull request #390 from keflavich/url_helpers_imports

Fix six imports
decode content before sending to parser
add a regression test for previous change
add supporting data file
content is not a consistent type.
UKIDSS: decode content
SDSS: try for that timeout yet again
AHA!  GOT YOU!  That stupid SDSS non-timeout failure was because an
earlier query was caching the query!
GAMA fix: requires specifying encoding='binary'
LAMDA: force everything to string type
IRSA: coerce to unicode
XMatch and unicode.
more unicode
ESO unicode
NVAS: FileContainer encoding
NRAO: Unicode coercion
add a py3 helper that decodes strings that can be decoded.