Add "empty_repo?" method to Repository role

Replaces two calls that this method simplifies

app/roles/repository.rb

@@ -8,6 +8,10 @@ module Repository
     false
   end
 
+  def empty_repo?
+    !repo_exists? || !has_commits?
+  end
+
   def commit(commit_id = nil)
     Commit.find_or_first(repo, commit_id, root_ref)
   end
@@ -38,7 +42,7 @@ module Repository
 
   def has_post_receive_file?
     hook_file = File.join(path_to_repo, 'hooks', 'post-receive')
-    File.exists?(hook_file) 
+    File.exists?(hook_file)
   end
 
   def tags
@@ -67,7 +71,7 @@ module Repository
 
   def repo_exists?
     @repo_exists ||= (repo && !repo.branches.empty?)
-  rescue 
+  rescue
     @repo_exists = false
   end
 
@@ -94,7 +98,7 @@ module Repository
     !!commit
   end
 
-  def root_ref 
+  def root_ref
     default_branch || "master"
   end
 
@@ -104,7 +108,7 @@ module Repository
 
   # Archive Project to .tar.gz
   #
-  # Already packed repo archives stored at 
+  # Already packed repo archives stored at
   # app_root/tmp/repositories/project_name/project_name-commit-id.tag.gz
   #
   def archive_repo ref