Ciuy

- Added: Changelog, Homepage, source code, bug tracker URI to metadata for RubyGems.
- Added: Figured out how to make Rubinius work on Travis. Targeting rbx-3 and rbx-4.

- Changed: Refactor to use frozen string literals.
- Changed: Ruby versions supported (running in Travis): 1.9.3, 2.1.10, 2.2.9, 2.3.8, 2.4.6, 2.5.5, 2.6.3, 2.7.0-preview1, jruby-19mode, jruby-head, ruby-head, truffleruby.
- Added: Documentación en español.
- Added: This CHANGELOG file.
- Added: CI on GitLab (`rake test` + `rubocop`).
- Added: truffleruby in the Travis build.
- Removed: Post-install message warning about numbers with less than 6 digits.

Added

- Added command line arguments.

Changed

- `ciuy.random()` is now `ciuy.random_ci()`

Changed

- Added linting with `flake8` to `travis-ci` config.
- Tests now use `pytest` instead of `nose2`.

- Added: Validate numbers are larger than 6 digits.
- Added: More documentation in README file.
- Added: Warning about numbers with less than 6 digits.

- Added: Support coverage in Travis for: Ruby 2.1.10, 2.3.7, 2.4.4, 2.5.1, 2.6.0-preview1. Allows Rubinius to fail in the build.
- Removed: Some unneeded minitest dependencies.