housekeeping
merge pull 94
doctests to unittests
doctests to unittests
doctests to unittests
formating
doctests to unittests
doctests to unittests
doctests to unittests
doctests to unittests
doctests to unittests
doctests to unittests
doctests to unittests
use datetime, date, timedelta directly
doctests to unittests
doctests to unittests
doctests to unittests
doctests to unittests
doctests to unittests
doctests to unittests