The `sort` methods were failing as responseTimes couldn't be cast to an
[]int. To fix this `ResponseTimes` now implements the `sort.Interface`
interface.
This commit abstracts out the body of `main()` and moves it into a separate
function `Runner` in `runner/runner.go`. Additonally two new types,
`Timer` and `Config` were introduced.
`Runner` takes in a `*Config` and returns the total number of points
written `totalPoints`, an slice of response times `responseTimes`, and a
timer with the starting and ending times of the test `*Timer`.
Michael Desa
Paul Dix