Update SDSS to the latest data release DR10

As mentioned in issue #219, the current SDSS code is using the API and data for DR5 whereas the most recent is DR10. This pull request includes the changes required to use data from DR10.

The PR also includes the necessary update for the offline unit tests as well as bug fixes for the online tests.

Note that the spectral templates have not changed since DR2. The URLs have been updated to DR7 which the most recent data release for which there is an API to obtain these templates.