Merge pull request #13 in KC/ponos from bugfix/PERF-209-fix-ponos-bro…

…ken-stats-for-low-cps to master

* commit 'df687401a4875c10894d592db01661b5a779c877':
  Code cleanup, follow module convention
  Simplify prune_intensities and improve calc_current_load on sudden drop in intensity.
  Make the intensities list never go below 2 items once it has 2 items.
  Fix test case for calc_current_load
  Fix problem with calculation current load

v1.5.0

        - Introduce dynamic configuration of max_concurrent.

        - Add edoc for ponos_task_runner_callbacks behvaiour.

v1.4.0

v1.3.0

        - Introduce max_concurrent option for load generators limiting
          how many concurrently ongoing tasks the load generator may
          spawn.

        - Add resources links in README.md

v1.2.2

v1.2.1

Minor cleanups.