To mark a task with a repeater as DONE, use C-- 1 C-c C-t, i.e., org-todo with a numeric prefix argument of ‘-1’.
(elpy-enable)
(when (require 'flycheck nil t)
(setq elpy-modules (delq 'elpy-module-flymake elpy-modules))
(add-hook 'elpy-mode-hook 'flycheck-mode))