Dev debugging improvements

[difernandez]

Motivation / Background

This Pull Request has been created to make debugging in development env easier, and closer to what we use in other projects.

Detail

The following changes were made:

• Adds pry-byebug
• Adds pry-byebug shortcuts
• Disables autocorrect for Rspec/Focus rule, to be able to use fit, fcontext and fdescribe when debugging without the "f" disappearing when saving

Additional information

pry-byebug

Checklist

Before submitting the PR make sure the following are checked:

• [x] This Pull Request is related to one change. Changes that are unrelated should be opened in separate PRs.
• [x] Commit message has a concise description of what changed and why.
• [x] Tests are added or updated if you fix a bug or add a feature.
• [x] Documentation has been added or updated if you add a feature or modify an existing one.
• [x] CHANGELOG files are updated for the changed libraries if there is a behavior change or additional feature (under the "Unreleased" heading if this is not a version change).
• [x] My changes don't introduce any linter rule violations.