Play 3.0.x and Pekko updates

[sentenza]

In order to use op-rabbit-play-json with Play v3.0.x this library should target Play 3, which is the only version supporting Pekko.

[pjfanning]

Hi @sentenza , thanks for the PR - I'll look into merging this if the tests pass and hopefully will get a release done within a few hours - all going well.

[pjfanning]

seems fine - I'll set up a v4.0.0 release - probably best to treat it is a major change due to the group id change on play libs

[sentenza]

@pjfanning thank you. Yes, this is not retro-compatible with Play 2.9 and in general Pekko can only be used with Play 3, so the previous version of this library cannot really be used either with Play 2.9 or Play 3.

I believe that those two issues are also related to wrong transitive dependencies imported via op-rabbit:3.0.0: lloydmeta/enumeratum#388 and playframework/play-grpc#499.

[pjfanning]

op-rabbit 4.0.0-SNAPSHOT is published with these changes

[sentenza]

@pjfanning I've already tested v4.0.0 and it's working as expected, solving all the cross-dependency issues. Thank you. :)