Added compatible logger injection

[AH-dark]

In the production environment, we often use a globally unique logger and cooperate with ELK, etc. to collect data. It may be necessary to add an implementation of a common logger.

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (68982eb) 84.97% compared to head (3c2bf4e) 84.97%.

❗ Your organization needs to install the Codecov GitHub app to enable full functionality.

Additional details and impacted files

@@           Coverage Diff           @@
##           master      #84   +/-   ##
=======================================
  Coverage   84.97%   84.97%           
=======================================
  Files          17       17           
  Lines        1278     1278           
=======================================
  Hits         1086     1086           
  Misses        160      160           
  Partials       32       32           

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[dxyinme]

I think we don't want to involve too many dependencies into project.
we prefer to let user to implement the dlog.PrintfLogger interface and pass it to dcron when it initialized.
you can add an example subomdule to teach how to use logrus or zap to take the place of default log.

anyway, thank you for your contribution.