Downloading: Accounted for empty files
Downloading: Accounted for empty files

Updated the Client class to accept downloads of 0 bytes (empty).

Signed-off-by: Leanne Clarke <74f8b7dbf822f341d6e2479ee87487ee7ddba183@windriver.com>

rcwoolley/device-cloud-python,rcwoolley/device-cloud-python