Error when / is missing at the end of the s3 directory

[dmsuehir]

If the sourceURL directory is missing a / at the end of the path, we get a minio client error message about needing a --recursive flag and it's not obvious what the problem is. Either adding the / to the end if it's a directory or giving a clearer error message would help.

$ kubectl logs kvc-resource-71fb9d16-4d5d-11e8-a4d9-0a580a480f75 
Added `s3` successfully.
mc: <ERROR> To copy a folder requires --recursive flag. Invalid arguments provided, please refer `mc <command> -h` for relevant documentation.