v2.7.0

Included in this release:

-fix(sizeDiff): unique fail message for size diffs 829d55b
Previously if snapshots were differently sized, an error would be thrown with the same message as if the image diff had passed the configured threshold. This gave the impression that jesst-image-snapshot was ignoring the failureThreshold config when differently sized images would fail even if the pixel or percentage difference between the images was below the configured threshold.

-feat(options): Add customDiffDir option 70a4b2e - closes #113
Allows users to configure the diff output directory that jest-image-snapshot should use