Allow `Adapter#broadcast` to accept kwargs

Allow to use async memory adapter without runner

PoC: Create a map_to option for subscribe data object

Fix typo mistake in README

Return uniquely event id (eid) for each broadcast call

PoC: runner for subscribers

Add hanami-events-cloud_pubsub adapter to README

Feature/match by regexp

Allow passing extra args to subscribe in Events::Mixin

Add rubocop

Add base rubocop file and fix styles in code

Feature/callable objects

feature: preparations for customizable serializers

https://github.com/hanami/events/issues/58

Add LICENSE file

Add XML formatter

Yard documentation

[FIX #51] Allow to use different streams for Redis adapter

[FIX #28] Wrap redis instance into connection pool

Use BRPOPLPUSH for save events in event store

Add event id to event data

Add documentation for Subscriber class

Introduce mutant testing

Rename and move HanderRunner

Use redis lists instead pubsub

[FIX #6] Implement subscribe_to method and Subscriber module

[FIX #36] Split Memory Adapter to: Memory sync and Memory async

Make memory adapter async

[FIX #29] Rename Hanami::Events#build to Hanami::Events#initialize

Refactoring of events meta information

Introduce events formatters