Question: Why ignore .json files in karma?

Hey @leonli, hope this finds you well!

Looking at the blame log, I see you're the author of `karma.conf.js`. Recently, I ran into an issue with this line: https://github.com/erikras/react-redux-universal-hot-example/blob/master/karma.conf.js#L50

It causes `require('./foo.json')` to fail, but `require('./foo')` works. This is not consistent with the non-test build environment.

Do you remember why this line is present? I removed it, and things seem to work OK for now.

Thanks!