Feature: Slack integration (#783)

- Integrations architecture
- Slack integration

spec/jobs/hook_job_spec.rb

@@ -0,0 +1,15 @@
+require 'rails_helper'
+
+RSpec.describe HookJob, type: :job do
+  subject(:job) { described_class.perform_later(hook, message) }
+
+  let(:account) { create(:account) }
+  let(:hook) { create(:integrations_hook, account: account) }
+  let(:message) { create(:message) }
+
+  it 'queues the job' do
+    expect { job }.to have_enqueued_job(described_class)
+      .with(hook, message)
+      .on_queue('integrations')
+  end
+end