0.08 - 2016/10/30
    - defer average and sum calculations until needed
    - tweak pod

0.06 - 2016/10/22
    - clarify wording in pod

0.05 - 2015/10/22
    - use List::Util sum0 to add up values
    - fix typos and bad DESCRIPTION

0.04 - 2015/10/22
    - renamed max_size to limit

0.03 - 2015/10/21
    - get 'size' from Array delegation
    - return oldest element in array, useful if you need to know what 
      gets deleted if the array is maxed 

0.01 - 2015/10/21
    - Initial release