Drop support for Mongoid 3 and 4 + fix after_fork callback

[johnnyshields]

• Drop support for Mongoid 3 and 4
• Perform disconnect on after_fork on all Mongoid versions

This gem's code has been quite stable so there's really no reason to continue to support Mongoid 3/4 (Mongoid 4 has been been EOL for 4 years now.)

[coveralls]

Coverage decreased (-0.6%) to 88.571% when pulling fce5b3e on johnnyshields:drop-mongoid-3-4 into d915199 on collectiveidea:master.

[coveralls]

Coverage decreased (-0.6%) to 88.571% when pulling 4d80dfe on johnnyshields:drop-mongoid-3-4 into d915199 on collectiveidea:master.

[dblock]

Can we remove mongoid_compatibility from .gemspec or is it used elsewhere?

[johnnyshields]

Can we remove mongoid_compatibility from .gemspec or is it used elsewhere?

I have removed mongoid_compatibility, it's not needed anymore.

[johnnyshields]

Please merge and cut a release

[dblock]

Merged. It's nice to see you here @johnnyshields. I added you to the repo maintainers and to rubygems so you can cut the release. Thanks for your help!

[johnnyshields]

Awesome, thanks 👍