Fix Rubocop warnings

[thdaraujo]

When running Rubocop, we get the following warnings:

The following cops were added to RuboCop, but are not configured. Please set Enabled to either `true` or `false` in your `.rubocop.yml` file.

Please also note that you can opt-in to new cops by default by adding this to your config:

and

The following cops were added to RuboCop, but are not configured. Please set Enabled to either `true` or `false` in your `.rubocop.yml` file.

Please also note that you can opt-in to new cops by default by adding this to your config:

Let's update the Rubocop YML file to solve these warnings.