astropy: IERS URL timing out

The IERS tables that describe Earth’s orientation ordinarily get downloaded from this URL stored in the utils.iers module:

In [18]: from astropy.utils import iers

In [19]: iers.IERS_A_URL
Out[19]: 'http://maia.usno.navy.mil/ser7/finals2000A.all'

At present (and maybe for some time now), the above URL times out always. I found from the IERS webpage that there’s an alternative server which is serving the table appropriately here, at

http://toshi.nofs.navy.mil/ser7/finals2000A.all

This is causing a bunch of mysterious IERS warnings and errors in astroplan. Should we switch the hard-coded URL in astropy to the backup URL until the normal server is restored?

I checked to see if the IERS webpage maintainers have an email address that we can contact, but they left only a phone number on the webpage (for the adventurous: 202-762-1518).

cc @eteq (@kvyh – heads up, astroplan tests may fail due to this problem even if the code you wrote is fine)