Since #19875, Sage ships MathJax 2.6.1.

MathJax 2.7.4 was released 2018-04-03.

It brings accessibility improvements, among other things.

For a more exhaustive list of changes, see the changelogs for
MathJax 2.7,
MathJax 2.7.1,
MathJax 2.7.2,
MathJax 2.7.3,
MathJax 2.7.4.

Tarball: https://sites.math.washington.edu/~palmieri/Sage/mathjax-2.7.4.tar.gz

CC: @egourgoulhon @embray @kiwifb @jdemeyer @jhpalmieri @kcrisman @miguelmarco @novoselt @haraldschilly @slel @sagetrac-tmonteil @vbraun

Component: packages: standard

Keywords: mathjax

Author: John Palmieri

Branch/Commit: b7a8142

Reviewer: François Bissey

Issue created by migration from https://trac.sagemath.org/ticket/25032