fix link to @plotly/mathjax-v2 in test

Author: archmoj

test/jasmine/bundle_tests/mathjax_test.js

@@ -11,8 +11,8 @@ var mathjaxVersion = __karma__.config.mathjaxVersion;
 describe('Test MathJax v' + mathjaxVersion + ':', function() {
     beforeAll(function(done) {
         var src = mathjaxVersion === 3 ?
-            '/base/node_modules/mathjax-v3/es5/tex-svg.js' :
-            '/base/node_modules/mathjax-v2/MathJax.js?config=TeX-AMS-MML_SVG';
+            '/base/node_modules/@plotly/mathjax-v3/es5/tex-svg.js' :
+            '/base/node_modules/@plotly/mathjax-v2/MathJax.js?config=TeX-AMS-MML_SVG';
 
         // N.B. we have to load MathJax "dynamically" as Karma
         // does not undefined the MathJax's `?config=` parameter.