Update Mathjax version to include a11y

cms/djangoapps/pipeline_js/js/xmodule.js

@@ -18,7 +18,7 @@ define(
         window._ = _;
 
         $script(
-            '//cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.1/MathJax.js' +
+            'https://cdn.jsdelivr.net/npm/mathjax@2.7.5/MathJax.js' +
             '?config=TeX-MML-AM_SVG&delayStartupUntil=configured',
             'mathjax',
             function() {

cms/static/cms/js/require-config.js

@@ -55,7 +55,9 @@
             // the option as displayed in the context menu to false.
             // When upgrading to 2.6, check if this variable name changed.
             window.MathJax = {
-                menuSettings: {CHTMLpreview: false}
+                menuSettings: {
+                    CHTMLpreview: false
+                }
             };
         };
 
@@ -131,7 +133,7 @@
             'lang_edx': 'js/src/lang_edx',
 
             // externally hosted files
-            mathjax: '//cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.1/MathJax.js?config=TeX-MML-AM_SVG&delayStartupUntil=configured',  // eslint-disable-line max-len
+            mathjax: 'https://cdn.jsdelivr.net/npm/mathjax@2.7.5/MathJax.js?config=TeX-MML-AM_SVG&delayStartupUntil=configured',  // eslint-disable-line max-len
             'youtube': [
                 // youtube URL does not end in '.js'. We add '?noext' to the path so
                 // that require.js adds the '.js' to the query component of the URL,

cms/static/cms/js/spec/main.js

@@ -69,7 +69,7 @@
             'domReady': 'xmodule_js/common_static/js/vendor/domReady',
             'URI': 'xmodule_js/common_static/js/vendor/URI.min',
             'mock-ajax': 'xmodule_js/common_static/js/vendor/mock-ajax',
-            mathjax: '//cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.1/MathJax.js?config=TeX-MML-AM_SVG&delayStartupUntil=configured',   // eslint-disable-line max-len
+            mathjax: 'https://cdn.jsdelivr.net/npm/mathjax@2.7.5/MathJax.js?config=TeX-MML-AM_SVG&delayStartupUntil=configured',   // eslint-disable-line max-len
             'youtube': '//www.youtube.com/player_api?noext',
             'js/src/ajax_prefix': 'xmodule_js/common_static/js/src/ajax_prefix',
             'js/spec/test_utils': 'js/spec/test_utils'

cms/static/cms/js/spec/main_squire.js

@@ -48,7 +48,7 @@
             'draggabilly': 'xmodule_js/common_static/js/vendor/draggabilly',
             'domReady': 'xmodule_js/common_static/js/vendor/domReady',
             'URI': 'xmodule_js/common_static/js/vendor/URI.min',
-            mathjax: '//cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.1/MathJax.js?config=TeX-MML-AM_SVG&delayStartupUntil=configured',   // eslint-disable-line max-len
+            mathjax: 'https://cdn.jsdelivr.net/npm/mathjax@2.7.5/MathJax.js?config=TeX-MML-AM_SVG&delayStartupUntil=configured',   // eslint-disable-line max-len
             'youtube': '//www.youtube.com/player_api?noext',
             'js/src/ajax_prefix': 'xmodule_js/common_static/js/src/ajax_prefix'
         },