Merge pull request #428 from wallyworld/download-tools-retry

Add retry to curl download of tool in cloud init

Add retry arg to curl used to download tools in cloud init.
Fixes lp:1349989
Merge pull request #510 from wallyworld/download-tools-retry-master

Add retry to curl download of tool in cloud init

Forward port of pull request 428

Add retry arg to curl used to download tools in cloud init.
Fixes lp:1349989