Add headers to image request

[micahlt]

I have a use case where I'm using authorization headers, and the React Native Image component allows me to pass those directly into the source of an Image. It would be great if the same thing would work with this library!

Theoretical example:

<FasterImageView source={{
  uri: src,
  headers: {
    Authorization: `Bearer ${token}`,
  },
 }} />

[gtokman]

@micahlt live on latest version!

[micahlt]

Wonderful! Thanks so much!