Updated the extentions on travis

~~The imagick tests reveal that we are now using a deprecated method: flattenImages.~~

**EDIT: I've provided a fix, and the tests are passing now.**
See: https://github.com/avalanche123/Imagine/blob/a8ff79d501a0197740bc15074ce288ca0119d068/lib/Imagine/Gmagick/Image.php#L680.