Add missing spec for ProtectedBranches::CreateService

spec/services/protected_branches/create_service_spec.rb

+require 'spec_helper'
+
+describe ProtectedBranches::CreateService, services: true do
+  let(:project) { create(:empty_project) }
+  let(:user) { project.owner }
+  let(:params) do
+    {
+      name: 'master',
+      merge_access_levels_attributes: [ { access_level: Gitlab::Access::MASTER } ],
+      push_access_levels_attributes: [ { access_level: Gitlab::Access::MASTER } ]
+    }
+  end
+
+  describe '#execute' do
+    subject(:service) { described_class.new(project, user, params) }
+
+    it 'creates a new protected branch' do
+      expect { service.execute }.to change(ProtectedBranch, :count).by(1)
+      expect(project.protected_branches.last.push_access_levels.map(&:access_level)).to eq([Gitlab::Access::MASTER])
+      expect(project.protected_branches.last.merge_access_levels.map(&:access_level)).to eq([Gitlab::Access::MASTER])
+    end
+  end
+end