volume_test has a strange definition of maximum and minimum

The volume_test script checks whether the detected volume level for audio devices on the system is within a specified 'minimum' and 'maximum' range. Bizarelly though they fail if the volume is also equal to either of these values. In mathematics ' the maximum and minimum of a set (as defined in set theory) are the greatest and least element in the set'. The set here being defined as the allowable values for the volume level, if it is defined as 50-100 then any value including 50 and 100 within that range are valid. Unfortunately it's not possible to change mathematics to make this test work so it needs to be fixed.