Add .babelrc (and similar) to .npmignore

[yofreke]

I suddenly started getting build errors on the new version of debug. It's likely because babel-loader is seeing the .babelrc in node_modules/debug, which is then for some reason causing issues (because it cannot find presets relative to that babelrc).

While I plan on working around this using config, I do still have the question: Do these config files describing source structure belong in the npm package?

[escwald]

I had this issue as well, but it was "fixed" when I upgraded my npm with
npm install npm@latest -g

I have also added a pull request (#383) that should hide the .babelrc, but still make it work with the tests that use it.

[yamikuronue]

My PR (#378) will fix this by removing Babel entirely.

[yofreke]

Ty all