gnu: Add ruby-saikuro-treemap.

* gnu/packages/ruby.scm (ruby-saikuro-treemap): New variable.

gnu: Add ruby-json-pure.

* gnu/packages/ruby.scm (ruby-json-pure): New variable.

gnu: Add ruby-utils.

* gnu/packages/ruby.scm (ruby-utils): New variable.

gnu: Add ruby-pstree.

* gnu/packages/ruby.scm (ruby-pstree): New variable.

gnu: Add ruby-term-ansicolor.

* gnu/packages/ruby.scm (ruby-term-ansicolor): New variable.

gnu: Add ruby-minitest-tu-shim.

* gnu/packages/ruby.scm (ruby-minitest-tu-shim): New variable.

gnu: Add ruby-gem-hadar.

* gnu/packages/ruby.scm (ruby-gem-hadar): New variable.

gnu: Add ruby-minitest-4.

* gnu/packages/ruby.scm (ruby-minitest-4): New variable.

gnu: Add ruby-tins.

* gnu/packages/ruby.scm (ruby-tins): New variable.

gnu: Add ruby-sdoc.

* gnu/packages/ruby.scm (ruby-sdoc): New variable.

gnu: Add ruby-pry-editline.

* gnu/packages/ruby.scm (ruby-pry-editline): New variable.

gnu: Add ruby-ci-reporter.

* gnu/packages/ruby.scm (ruby-ci-reporter): New variable.

gnu: Add ruby-atoulme-saikuro.

* gnu/packages/ruby.scm (ruby-atoulme-saikuro): New variable.

gnu: Add ruby-simplecov.

* gnu/packages/ruby.scm (ruby-simplecov): New variable.

gnu: ruby-simplecov-html: Fix hash and disable tests.

* gnu/packages/ruby.scm (ruby-simplecov-html)[source]: Replace incorrect
  hash.
[arguments]: Disable tests.

gnu: Add ruby-net-ssh.

* gnu/packages/ruby.scm (ruby-net-ssh): New variable.

gnu: Add ruby-mocha.

* gnu/packages/ruby.scm (ruby-mocha): New variable.

gnu: Add ruby-redcarpet.

* gnu/packages/ruby.scm (ruby-redcarpet): New variable.

gnu: Add ruby-introspection.

* gnu/packages/ruby.scm (ruby-introspection): New variable.

gnu: Add ruby-instantiator.

* gnu/packages/ruby.scm (ruby-instantiator): New variable.