Update mathjs

[ecc521]

NPM is now showing a security vulnerability all older versions of mathjs.

While I have not checked to see if this library is vulnerable, the very inclusion of a dependency with vulnerabilities makes this library currently unusable under many security policies.

mathjs does not appear to be used heavily, so it should be relatively easy to update. The latest version of mathjs seems to be working relatively similarly, though not exactly the same.

[MuazOthman]

This has been addressed in #6

Thanks for the review, @yongjun21. Can you please publish a new version to NPM so the fix is easily consumed by the community?