This helps the test pass. I think there is a bug with pngjs where it's...

This helps the test pass. I think there is a bug with pngjs where it's emitting end before it's actually done writing.

lib/psd/image_exports/png.coffee

@@ -15,6 +15,5 @@ module.exports =
       @toPng().then (image) ->
         image
           .pack()
-          .on('end', resolve)
+          .on 'end', -> setTimeout(resolve, 1)
           .pipe(fs.createWriteStream(output))
-