fix: ignoreWarnings not working on webpack 5

[ImLunaHey]

if this PR isn't wanted im happy to maintain my own fork. 🙏

also im not 100% how to fix the error the tests are throwing. 🤔
if someone can point me in the right direction ill be happy to fix them up.

closes: #90 and #81

[RoccoC]

This is great, thank you!

A few considerations:

• technically this is a breaking change since the plugin will no longer work with webpack versions < 5, so we should bump the version to 3.0.0
• the failing test is due to changes in the postcss-loader config API, but after fixing this I found that the original test case is no longer valid for webpack 5 and the latest version of autoprefixer. I think it's best to remove the Should handle warning from child compiler test case from tests/test.spec.ts, as well as any related files that are no longer needed for the test (tests/childWarning.js, tests/test.css). This means we can also remove the css loaders/plugins from tests/webpack.config.ts and package dependencies, too.
• I know that TSLint is long deprecated, but I think it would be great to replace it with ESLint (or at least keep it around until we do).

Thanks again! 🙏

[ImLunaHey]

Let me get this fixed up. 🙏

[ImLunaHey]

@RoccoC let me know if that resolves all the issues. 🙏

[ImLunaHey]

bump ⬆️

[RoccoC]

bump ⬆️

There's an issue when running npm test, but otherwise all looks good! Thanks again, and so sorry for the delay!

[ImLunaHey]

if tests need to pass before merging then a CI action should be added to enforce that.

[ImLunaHey]

i cannot get the tests to run locally. they just sit there without doing anything.

➜  webpack-build-notifier git:(master) ✗ npm run test -- --verbose

> webpack-build-notifier@3.0.0 test
> jest --verbose


 RUNS  tests/test.spec.ts

[RoccoC]

i cannot get the tests to run locally. they just sit there without doing anything.

I'll get these fixed up and merged. Thanks for your PR.

[RoccoC]

if tests need to pass before merging then a CI action should be added to enforce that.

Thanks for flagging this. Looks like TravisCI was no longer working. I went ahead and migrated to CircleCI.

[chadlwilson]

Thanks for the work here!

Just to confirm - given the major version bump, does this drop support for Webpack 4 or still backwards compatible?