Save diff image if test failed
* Compare images with bytes for better results
* Fixes #4
Remove if check, because free can be called on NULL
Correct variable name
Take account of retina scale for diff images
Apple recommend 0.0 for automatically set to the scale factor of the device’s main screen
Merge pull request #5 from AutoScout24/image-diff

Save diff image if test failed
Add comment why MIN is used
Add missing assert
Merge pull request #6 from AutoScout24/image-compare-changes

Compare images with bytes for better results
Add default value FB_REFERENCE_IMAGE_DIR
Add test target + image comparison tests
Fix plist path