Add `Dry::Types::Hash::Schema.merge`

[waiting-for-dev]

It's also aliased as .compose.

I submit this PR in relation with https://github.com/dry-rb/dry-struct/pull/139

It moves composition to the fundamental piece of a Dry::Struct, a Dry::Types::Hash::Schema.

If this PR is accepted I'll modify the other one accordingly so it makes use of the new method.

Key transformation and type transformation work in a different way due to how they are implemented, but I haven't studied why it is this way. Any feedback is welcomed :)

[waiting-for-dev]

Hey @solnic, a downside of this automation of Codacy you added is that its notifications come with your name (and so, consequently, the notification emails)... This way it is easy to miss a more personalized and important message written by you (as probably people will let automatic code review messages for later)

[solnic]

Hey @solnic, a downside of this automation of Codacy you added is that its notifications come with your name (and so, consequently, the notification emails)... This way it is easy to miss a more personalized and important message written by you (as probably people will let automatic code review messages for later)

that's not good. I'll see if this can be changed, if not - we'll go back to houndci.

[solnic]

@waiting-for-dev could you rebase this on top of master please?

[solnic]

@waiting-for-dev I disabled codeclimate and houndci and I also configured dry-bot to be the author of codacy comments. We'll see how that works once you push something new here 😄

[waiting-for-dev]

@solnic I rebased to master and fixed two issues I introduced by mistake.

Yep! Codacy is now much helpful :smiley:

[flash-gordon]

@waiting-for-dev oh, hold on a sec. We have Schema#schema already, we should just call schema(other.keys) in merge. WDYT?

[waiting-for-dev]

Thanks for your review @flash-gordon , I forced a new push