
When nothing specified in "volume unset" command, there will be an error message says that the "--properties" option is required, it is unusual behaviour, this patch fix it and also add unit test for it. Also, this patch add unit test for "volume show" command by the way. Change-Id: I5b5d587670acf0af4262b8521292455bf9f60fe5 Partial-bug: #1588588