If no arguments are provided while executing neutron quota-update
instead of printing the current quota values it will throw an error
message "Must specify new values to update quota"
Added unit test to verify that the exception is raised when no
arguments are provided to quota update
Includes release notes.
DocImpact
Closes-Bug: #1597552
Change-Id: I476991c39eafa16148f0cc3252ae5c26b9c8cbfc