[ANN] hoe 3.21.0 Released

hoe version 3.21.0 has been released!

* home: <http://www.zenspider.com/projects/hoe.html>
* code: <https://github.com/seattlerb/hoe>
* bugs: <https://github.com/seattlerb/hoe/issues>
* rdoc: <http://docs.seattlerb.org/hoe/>
* doco: <http://docs.seattlerb.org/hoe/Hoe.pdf>
* clog: <https://github.com/seattlerb/hoe/blob/master/History.rdoc>
* other: <http://github.com/jbarnette/hoe-plugin-examples>

Hoe is a rake/rubygems helper for project Rakefiles. It helps you
manage, maintain, and release your project and includes a dynamic
plug-in system allowing for easy extensibility. Hoe ships with
plug-ins for all your usual project tasks including rdoc generation,
testing, packaging, deployment, and announcement.

See class rdoc for help. Hint: `ri Hoe` or any of the plugins listed
below.

For extra goodness, see: http://docs.seattlerb.org/hoe/Hoe.pdf

Changes:

### 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.