Log Message:
Update to 0.13

Upstream changes:
0.13      2018-04-18 00:46:01-07:00 America/Los_Angeles
          - allow a single argument to `rand_enum` as long as it's an arrayref
          Thanks to NEILB (Neil Bowers) for the suggestion
          Thanks to jjatria (José Joaquin Atria) for doing the work
          - upgrade to Dist::Zilla
          Thanks to jjatria (José Joaquin Atria) for the pull request
          - use Test::MockTime to avoid off-by-a-second bogus test failures
          Thanks to jjatria (José Joaquin Atria) for the pull request
          - fix mismatched docs and implementation for `rand_chars`
            now both are correct
          Thanks to jjatria (José Joaquin Atria) for the pull request
          - better error handling in `rand_time`
          Thanks to jjatria (José Joaquin Atria) for the pull request