git - rugged: add tags to the refspec

* ensure we also add refs/tags to the refspec
* also add download_tags to the options for good measure

Fixes: #1416

Author: b4ldr

lib/r10k/git/rugged/bare_repository.rb

@@ -59,8 +59,8 @@ def fetch(remote_name='origin')
     remote = remotes[remote_name]
     proxy = R10K::Git.get_proxy_for_remote(remote)
 
-    options = {:credentials => credentials, :prune => true, :proxy_url => proxy}
-    refspecs = ['+refs/heads/*:refs/heads/*']
+    options = {:credentials => credentials, :prune => true, :proxy_url => proxy, :download_tags => true}
+    refspecs = ['+refs/heads/*:refs/heads/*', '+refs/tags/*:refs/tags/*']
 
     results = nil