[Perl/perl5] 6840bb: Tick off 5.31.7 on 2019-12-20

[Nicolas R.]

  Branch: refs/heads/blead
  Home:   https://github.com/Perl/perl5
  Commit: 6840bbf495a31c12e188e97c979f715ca0b32207
      
https://github.com/Perl/perl5/commit/6840bbf495a31c12e188e97c979f715ca0b32207
  Author: Nicolas R <atoo...@cpan.org>
  Date:   2019-12-20 (Fri, 20 Dec 2019)

  Changed paths:
    M Porting/release_schedule.pod

  Log Message:
  -----------
  Tick off 5.31.7 on 2019-12-20