Feature: Slack integration (#783)

- Integrations architecture
- Slack integration

spec/lib/integrations/slack/hook_builder_spec.rb

@@ -0,0 +1,22 @@
+require 'rails_helper'
+
+describe Integrations::Slack::HookBuilder do
+  let(:account) { create(:account) }
+  let(:code) { SecureRandom.hex }
+  let(:token) { SecureRandom.hex }
+
+  describe '#perform' do
+    it 'creates hook' do
+      hooks_count = account.hooks.count
+
+      builder = described_class.new(account: account, code: code)
+      builder.stub(:fetch_access_token) { token }
+
+      builder.perform
+      expect(account.hooks.count).to eql(hooks_count + 1)
+
+      hook = account.hooks.last
+      expect(hook.access_token).to eql(token)
+    end
+  end
+end