Add ability to compute and track minimum

[baryluk]

I would like to compute "minimum" of the each test. Not average. And also use it for 'fastest' filtering.

As a bonus, lower 5th percentile would be also useful, and would be nice to configure. (minimum is 0th percentile, median is 50th percentile, for example).

[jdalton]

Hi @baryluk!

Each benchmark object provides a stats collection that you can use to compute a variety of things. Have you tried accessing/iterating over them?