Log Message:
p5-JSON: update to 2.97000.

2.97000 2017-11-21
    - updated backportPP with JSON::PP 2.97000
    - use 5 digit minor version number for a while to avoid
      confusion
    - fixed is_bool to use blessed() instead of ref()

2.96 2017-11-20
    - fixed packaging issue
    - updated backportPP with JSON::PP 2.96
    - not to use newer Test::More features (RT-122421; ilmari++)

2.95 2017-11-20
    - updated backportPP with JSON::PP 2.95