Log Message:
Update to 0.27

Upstream changes:
0.27   2019-01-19

- If test_all_dependents() cannot find anything that depends on the given
  module it runs `plan( skip_all => ... )` rather than `plan(0)`. The latter
  causes the test to fail. While this should never really happen in normal use
  it can be an issue when MetaCPAN is having problems (such as
  https://github.com/metacpan/metacpan-web/issues/2139).

- Explicitly add JSON::PP to our prereqs. This seems to fix an issue with
  testing on Perl 5.10.1. This module is needed by something in our dependency
  chain but it doesn't get installed.