Update built-in IERS files - #10376

@mhvk - there is a real doctest failure now:

______________________________ [doctest] iers.rst ______________________________

155 In most cases the automatic interface will suffice, but you may need to

156 directly load and manipulate IERS tables.  IERS-B values are provided as part

157 of astropy and can be used to calculate time offsets and polar motion

158 directly, or set up for internal use in further time and coordinate

159 transformations.  For example::

160 

161   >>> from astropy.utils import iers

162   >>> t = Time('2010:001')

163   >>> iers_b = iers.IERS_B.open()

164   >>> iers_b.ut1_utc(t)  # doctest: +FLOAT_CMP

Expected:

    <Quantity 0.1140827 s>

Got:

    <Quantity 0.114033 s>

/home/travis/build/astropy/astropy/docs/utils/iers.rst:164: DocTestFailure

Could you take a look to see what might be going on? I just used the update_builtin_iers.sh script to update the files

@astrofrog - the IERS B files seem a lot less "permanent" than one would think. I certainly have seen similarly large ranges of it changed by small amounts, presumably due to a reanalysis or so. Since that really is not under our control, my sense would be to simply adjust the doctest...

@mhvk - ok thanks!

@mhvk - could you review/approve this? (one of the last things that needs to be included for the 4.1 release)

@mhvk - thanks! Just to check, we should update this file in bugfix releases e.g. for the LTS version too, right?

Wait a minute. Remote data job failed. See #10386

Yes, LTS should be updated too. I've seen the discussion about the failure but am so far failing to understand. Hope to check later.