Show offending value in 'no-magic-numbers' error message

[dariobanfi]

PR checklist

• Addresses an existing issue: improve no-magic-numbers error message to contain the offending value #2067
• New feature, bugfix, or enhancement
  • Includes tests
• Documentation update

Overview of change:

I just fixed an issue about showing the offending value for no-magic-numbers rule.

Before:

'magic numbers' are not allowed

Now:

'magic numbers' are not allowed: 3

CHANGELOG.md entry:

I didn't create one for such a small thing. Should I?

[palantirtech]

Thanks for your interest in palantir/tslint, @dariobanfi! Before we can accept your pull request, you need to sign our contributor license agreement - just visit https://cla.palantir.com/ and follow the instructions. Once you sign, I'll automatically update this pull request.

[JoshuaKGoldberg]

Super, thanks @dariobanfi!

Changelog entry

You should get credit for this! 😊

Let's say something like:

[enhancement] Added failing number to the magic-numbers rule