feat: headers support function 'Last-Modified': () => new Date() (#749)

[Nhjkl]

#749 I think we can solve this problem in this way

webpackDevMiddleware(compiler, {
  headers: {
    'Last-Modified': () => new Date()
  }
})

[alexander-akait]

I think better to allow headers will be function

[Nhjkl]

Good idea

Can it fit into the schedule

[alexander-akait]

Yes, feel free to improve, even more, maybe we can send req/res/etc as arguments, so you can create more complex things

[Nhjkl]

Agree with.

Looking forward to the update

[Nhjkl]

I don't know much English, and this is my first time to submit PR.

Do you mean I will continue to improve, or you will improve yourself

[alexander-akait]

Do you mean I will continue to improve, or you will improve yourself

You can continue improve, it is easy to implement

[Nhjkl]

ok