Change compliant with latest version

Make the test check for the new `^` instead of `**`.

test/unit/publicapi.test.js

diff --git a/test/unit/publicapi.test.js b/test/unit/publicapi.test.js
index 285699c..efeb9c2 100644
--- a/test/unit/publicapi.test.js
+++ b/test/unit/publicapi.test.js
@@ -145,7 +145,7 @@
       mq.latex('3x+\\ 4');
       assert.equal(mq.text(), '3*x+ 4');
       mq.latex('x^2');
-      assert.equal(mq.text(), 'x**2')
+      assert.equal(mq.text(), 'x^2')
     });
 
     test('.moveToDirEnd(dir)', function() {