Fix some typos in stats docs
Remove broken link

One of the link containing more information on the function `super()`
was broken. Fixes #1376
Skip doctests that require a remote server
Specify fixed versions for Matplotlib, Sphinx, and Cython to avoid breaking builds when new versions are released.
Add support for REMOTE flag to doctests.
Document new REMOTE flag in doctests.  Remove out-of-date information
about doctest flags remaining in the output.
Mark some doctests as +REMOTE
Merge pull request #1842 from astrofrog/switch-wheel-servers

Switch wheel server order to use mirror
Remove spurious warning from printwcs, as reported by Maik Riechert on astropy@scipy.org
Add changelog entry.
Merge pull request #40 from mdboom/docs/disable-remote-doctests

Add REMOTE flag to doctests so we can disable tests that require remote data
Added known issue for MAGEIA-2 and 3 install bug
Updated wording following @embray's suggestion
Added a comment to remind ourselves that e-terms should indeed be computed using the equinox, and not the observing time/epoch.
Merge pull request #1496 from astrofrog/clarify-eterms

E-term calculation uses equinox but should use observation date
Merge pull request #1853 from astrofrog/mageia-known-issue

Mageia known issue
Renamed doctest +REMOTE option to +REMOTE_DATA
Update CHANGES.rst

Fixed extra indentation
Merge pull request #1843 from astrofrog/disable-remote-doctest

Skip doctests that require a remote server
Merge pull request #1819 from gabraganca/super_docs

Remove broken link