Bump js-slang to latest (0.3.1)

[alcen]

The current version of js-slang used will crash the Playground when the Substituter is used with libraries like RUNES. In version 0.3.1, this was fixed, and running programs like this will no longer cause a crash:

function stackn_2(n, pic) {
    return n === 1
        ? pic
        : stack_frac(1 / n, pic, stackn_2(n - 1, pic));
}
show(stackn_2(3, heart));

[coveralls]

Pull Request Test Coverage Report for Build 3216

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 36.89%

---

Totals
Change from base Build 3201:	0.0%
Covered Lines:	2671
Relevant Lines:	6486

---

💛 - Coveralls

[Aulud]

I see the js-slang package has been updated to v0.3.1 on npm. However, on the https://github.com/source-academy/js-slang repo, the package.json has not been updated to v0.3.1 nor is there a v0.3.1 branch nor is there any documentation on the changes from v0.2.6 to v0.3.1.

@openorclose Is it safe to bump the version?

[alcen]

I see the js-slang package has been updated to v0.3.1 on npm. However, on the https://github.com/source-academy/js-slang repo, the package.json has not been updated to v0.3.1 nor is there a v0.3.1 branch nor is there any documentation on the changes from v0.2.6 to v0.3.1.
@openorclose Is it safe to bump the version?

Yeah, I am aware of this and have highlighted it. Well, seems it has just been merged as I was writing this comment haha: source-academy/js-slang#320

[openorclose]

I see the js-slang package has been updated to v0.3.1 on npm. However, on the https://github.com/source-academy/js-slang repo, the package.json has not been updated to v0.3.1 nor is there a v0.3.1 branch nor is there any documentation on the changes from v0.2.6 to v0.3.1.

@openorclose Is it safe to bump the version?

I have approved and merged the pr already

[geshuming]

ok lgtm