Downloading already downloaded file on each Chef run

[karmi]

Current version of Ark downloads the same file over and over on Chef runs, making repeatably testing cookbooks using it in Vagrant very hard and causing unnecessary traffic elsewhere.

There's a patch at fewbytes-cookbooks/ark@a5f30f18ff2cc648a85583df49f7711bf073f76c.

This causes problems in the Elasticsearch cookbook: elasticsearch/cookbook-elasticsearch#104.