add emails service specs

spec/services/emails/create_service_spec.rb

+require 'spec_helper'
+
+describe Emails::CreateService, services: true do
+  let(:user) { create(:user) }
+  let(:opts) { { email: 'new@email.com' } }
+
+  subject(:service) { described_class.new(user, opts) }
+
+  describe '#execute' do
+    it 'creates an email with valid attributes' do
+      expect { service.execute }.to change { Email.count }.by(1)
+      expect(Email.where(opts)).not_to be_empty
+    end
+
+    it 'has the right user association' do
+      service.execute
+
+      expect(user.emails).to eq(Email.where(opts))
+    end
+  end
+end

spec/services/emails/destroy_service_spec.rb

+require 'spec_helper'
+
+describe Emails::DestroyService, services: true do
+  let!(:user) { create(:user) }
+  let!(:email) { create(:email, user: user) }
+
+  subject(:service) { described_class.new(user, opts) }
+
+  describe '#execute' do
+    it 'creates an email with valid attributes' do
+      expect { service.execute }.to change { user.emails.count }.by(-1)
+    end
+  end
+end