Log Message:
devel/hoe: update to 3.21.0

Update hoe to 3.21.0.

=== 3.21.0 / 2020-01-11

* 2 minor enhancements:

  * Added support for wiki_uri and mailing_list_uri. (JuanitoFatas)
  * Load encrypted private key using ENV['GEM_PRIVATE_KEY_PASSPHRASE'] as \ 
passphrase. (larskanis)

* 5 bug fixes:

  * Add require_ruby_version for 2.1+. (MSP-Greg)
  * Fix a ruby 2.7 keyword arg deprecation. (anatol)
  * Fix debug_gem task when you have a signing_key and broken rubygems (< 3.1.0).
  * Fixed shadowed variable and json output for minitest's test:isolated task.
  * Minor tweak to make hoe load when openssl isn't available.

=== 3.20.0 / 2019-11-09

* 2 minor enhancements:

  * Added <test>:isolated task that runs tests in parallel. Replaces \ 
<test>:dep task.
  * Bumped rake dependency to be < 15.