dev-python/astroquery: Add astroquery ebuild

Package-Manager: portage-2.2.12

Adds the astroquery package, which recently released a 0.2 version.

This passes all tests in python 2.7, 3.3, and 3.4 except:
1. An SSL validation error in python2.7
2. Missing `keyring` module in python3.4

I think the first is just a configuration problem on my system, and the second is expected.