Add "empty_repo?" method to Repository role

Replaces two calls that this method simplifies

spec/roles/repository_spec.rb

@@ -0,0 +1,22 @@
+require 'spec_helper'
+
+describe Project, "Repository" do
+  let(:project) { build(:project) }
+
+  describe "#empty_repo?" do
+    it "should return true if the repo doesn't exist" do
+      project.stub(repo_exists?: false, has_commits?: true)
+      project.should be_empty_repo
+    end
+
+    it "should return true if the repo has commits" do
+      project.stub(repo_exists?: true, has_commits?: false)
+      project.should be_empty_repo
+    end
+
+    it "should return false if the repo exists and has commits" do
+      project.stub(repo_exists?: true, has_commits?: true)
+      project.should_not be_empty_repo
+    end
+  end
+end