Change Rails to RSpecRails

[marocchino]

While reading the documentation, I found that the menu name Breadcrumb did not match the lint prefix, so I fixed it. I skipped some basic checks because I didn't download it to my local environment, but I will do it if necessary.

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Before submitting the PR make sure the following are checked:

• Feature branch is up-to-date with master (if not - rebase it).
• [ ] Squashed related commits together.
• [ ] Added tests.
• Updated documentation.
• Added an entry to the CHANGELOG.md if the new code introduces user-observable changes.
• The build (bundle exec rake) passes (be sure to run this locally, since it may produce updated documentation that you will need to commit).

If you have created a new cop:

• [ ] Added the new cop to config/default.yml.
• [ ] The cop is configured as Enabled: pending in config/default.yml.
• [ ] The cop documents examples of good and bad code.
• [ ] The tests assert both that bad code is reported and that good code is not reported.
• [ ] Set VersionAdded: "<<next>>" in default/config.yml.

If you have modified an existing cop's configuration options:

• [ ] Set VersionChanged: "<<next>>" in config/default.yml.

[ydah]

Thank you!