Update README.md

[kehao-chen]

FIXME: The content type string could contain additional values like the charset.

// old
if (response.headers['content-type'] === 'application/json')
// new
if (response.headers['content-type'].includes('application/json')) 

[coveralls]

Coverage remained the same at 100.0% when pulling 2d0cb8a on HappyHackingNinja:master into a804c7f on request:master.

[analog-nico]

Thank you very much. However, I put the FIXME there intentionally to make the reader aware that the code is not safe. The way you fixed it is probably not safe either.

In actual production code a more robust solution like using the content-type library would be necessary. Should we put that into the README? What do you think?

[kehao-chen]

You right. I think it should not put unnecessary dependencies into the example code snippet. It's fine to keep what it is.

[analog-nico]

Anyways, you are pointing out something important. It is not helpful to mention a shortcoming and then not offering a solution. I agree, the example should remain simple. So I added a little note as you see in the commit linked above.

Thanks for bringing this up!