Created a basic Git Tag Push service

This is the first version, and only has the most basic information about
the tag that is created.

app/services/git_tag_push_service.rb

+class GitTagPushService
+  attr_accessor :project, :user, :push_data
+  def execute(project, user, ref)
+    @project, @user = project, user
+    @push_data = create_push_data(ref)
+    project.execute_hooks(@push_data.dup, :tag_push_hooks)
+  end
+
+  private
+
+  def create_push_data(ref)
+    data = {
+      ref: ref,
+      user_id: user.id,
+      user_name: user.name,
+      project_id: project.id,
+      repository: {
+        name: project.name,
+        url: project.url_to_repo,
+        description: project.description,
+        homepage: project.web_url
+      }
+    }
+  end
+end

spec/services/git_tag_push_service_spec.rb

+require 'spec_helper'
+
+describe GitTagPushService do
+  let (:user) { create :user }
+  let (:project) { create :project }
+  let (:service) { GitTagPushService.new }
+
+  before do
+    @ref = 'refs/tags/super-tag'
+  end
+
+  describe 'Git Tag Push Data' do
+    before do
+      service.execute(project, user, @ref)
+      @push_data = service.push_data
+    end
+
+    subject { @push_data }
+
+    it { should include(ref: @ref) }
+    it { should include(user_id: user.id) }
+    it { should include(user_name: user.name) }
+    it { should include(project_id: project.id) }
+
+    context 'With repository data' do
+      subject { @push_data[:repository] }
+
+      it { should include(name: project.name) }
+      it { should include(url: project.url_to_repo) }
+      it { should include(description: project.description) }
+      it { should include(homepage: project.web_url) }
+    end
+  end
+
+  describe "Web Hooks" do
+    context "execute web hooks" do
+      it "when pushing tags" do
+        project.should_receive(:execute_hooks)
+        service.execute(project, user, 'refs/tags/v1.0.0')
+      end
+    end
+  end
+end