Dependency bump release

• Scala 2.13.1
• Scala 2.12.10
• Circe 0.12.3
• Play! Json 2.8.0

The cats version

Complete rewrite of the API, based on cats. The core library now really focuses on creating and managing patches only. In particular, it doesn't take care of (de)serializing Json anymore.

The different diff algorithms are managed by providing an instance of Diff, and patches to be apply need to have an instance of Patch.

To add support for your Json AST, you simply need to provide an instance of Jsony, which is way smaller than the previous way of doing it.

Release 4.0.0-M3

Add safe deserialization for JsonPatch in Play Json (#92)

Release 4.0.0-M2

• Reintroduce remembering old values when computing diffs
• Fallback to raw string in pointer when integer capacity overflows
• Add support for Scala.JS

Release 3.1.0

This new version mainly brings support for Json Merge Patches and dependency updates.

See Milestone

Diffson 3.0.0

New major release with complete rework of how pointers are handled by
the library.

Other changes include:

• LCS implementations may be speeded-up by using precomputed hash of JSON objects.
• Patch operations avoid traversing several times collections when not needed. This results in much better performances when patching big JSON collections.
• Added support for incoming scala 2.13.
• Dropped support for scala 2.10.

To use it, see the README