Output size affects whether Image.Resize strips metadata

[yujiri8]

This might be a dupe of #194, but I'm not sure so I'm opening this.

Testing with this image:

Code:

package main

import (
	"io/ioutil"
	"os"

	"github.com/h2non/bimg"
)

func main() {
	var file, err = ioutil.ReadFile(os.Args[1])
	if err != nil {
		panic(err)
	}
	var img = bimg.NewImage(file)

	var out []byte
	out, err = img.Resize(1068, 0)
	if err != nil {
		panic(err)
	}
	ioutil.WriteFile("out.jpg", out, 0777)
}

If the width I resize it to is 1068 or less, the image comes out as expected - most metadata stripped, auto-rotated. If the width is 1069 or greater, metadata is not stripped, not even the orientation flag after rotating based on it - which means it comes out sideways.

The reason I think it's not the same thing is that in this comment on the other issue, @greut says that the metadata is stripped when the resize is a shrink, but the 1069 threshold is still a shrink in most dimensions for this image.