Astropy 0.3.2 fixes

Tests against astropy 0.3 weren't running; they were removed a while back with this message:
```
Date:   Sat Nov 9 11:17:11 2013 +0100

    disable stable tests on master (at least until 0.3 becomes "stable")
```

Well, it's been stable for quite a while, these tests should have been re-added.  We could have avoided https://github.com/astropy/astroquery/pull/335 at least.