Added max_mem_abs and min_mem_abs to ResourceWatcher
Added human2bytes to utils.py
Added test for max and min abs mem of ResourceWatcher
Added documentation for max and min abs mem of ResourceWatcher
Merge remote-tracking branch 'upstream/master' into ressource-watcher-mem-abs

Conflicts:
	circus/plugins/resource_watcher.py
	circus/tests/test_plugin_resource_watcher.py
	docs/source/for-ops/using-plugins.rst
Fixed flake8 warnings, adpated tests to async architecture
Removed useless backslashes
Merged max_mem_abs and max_mem (same for min)
Rewrote util.human2bytes + unit tests
fixed doc
Fixed if syntax
Polishing code
fixed typo
Add support to the add command for the 'singleton' option
Improve test_logging

Fix several issues in test_logging.py :

- Update the PYTHONPATH in order to make sure to use the tested
  version of Circus in the child process (was an issue when
  testing a development version of Circus, not installed in the
  system)
- Use Popen.terminate instead of using circusctl
- Use sys.executable instead of "python"
- Use a python script instead of bash
- Don't respawn the process instead of using a while loop
- Remove debugging comments
Merge pull request #769 from k4nar/fix_test_logging

Improve test_logging
Merge pull request #767 from wynnw/feature/add-singleton-option

Add support to the add command for the 'singleton' option
Merge branch 'ressource-watcher-mem-abs' of https://github.com/pomarec/circus into pomarec-ressource-watcher-mem-abs

Conflicts:
	circus/plugins/resource_watcher.py
	circus/util.py
Fix #771 — For some reason max can be int or long.
simplified the resource code
Merge branch 'pomarec-ressource-watcher-mem-abs'