Add missing converter: no-null-keyword

[da-snap]

Add converter for #173

PR Checklist

• Addresses an existing issue: fixes Missing converter: no-null-keyword #173
• That issue was marked as status: accepting prs

Overview

Add converter to convert no-null-keyword rule. Will add plugin eslint-plugin-no-null to settings.

[JoshuaKGoldberg]

Looking mostly great - just one addition please!

[da-snap]

I can't run the end-to-end tests. I have node 12.11.1 and tslint installed. It seems that the testArgs.join(" ") does not work for me.
When I try to log what is passed to exec I get something like this:
node [...]/tslint-to-eslint-config/bin/tslint-to-eslint-config " - - c o n f i g " "[...]/t s l i n t - t o - e s l i n t - c o n f i g / t e s t / t e s t s / s t a n d a l o n e t s l i n t . j s o n / . e s l i n t r c . j s o n " " - - t s l i n t " " [...] / t s l i n t - t o - e s l i n t - c o n f i g / t e s t / t e s t s / s t a n d a l o n e t s l i n t . j s o n / t s l i n t . j s o n "

Do you have an Idea what could be the issue? Since it works in circleci...

[JoshuaKGoldberg]

Super, thanks!

[JoshuaKGoldberg]

I'll take a look at the test shenanigans...

[JoshuaKGoldberg]

Ignoring end-to-end test failures as they're removed in master. 🤷‍♂