feat(rubocop): correct all rubocop erros

[Baelfire18]

Hi I was iniciating a proyecting using this awsome generator and i really it came with some default robocop errors, so I wanted to contribute and help correcting them. Can you review my PR?

What?

• Run rubocop fixes with the autocorrect feature
• Also manually correct some issues like:
  • SuggestExtensions: false.
  • Extend maximun to 120 characters per line.
  • Extend maximun of Metrics/MethodLength to 65 characters per line.
  • Extend maximun RSpec/MultipleExpectations to 25.
  • Extend maximum RSpec/ExampleLength to 35.
  • Extend maximun RSpec/MultipleMemoizedHelpers to 8.
  • Turn off in some lines Rails/Exit restriction.
• Specify the ruby version required by potassium gemspec.

Why?

• So it follows a linter concrete style and have more order.

How?

• Running rubocop -A.
• Correcting manually some mistakes and change rubocop rules.
• Ignoring some rules in specific code lines (Rails/Exit)

[rjherrera]

@Baelfire18 Hi there! Thanks for the pull request and sorry for the late reply.

We talked about this change internally and we appreciate the PR, however, we don't want to change those rules as they are the rules we use in many projects and that we are used to.

Regardless of that, we also saw that many changes that this PR introduces comply with the original set of rubocop rules, but were not fixed until now. If you want you could change this PR to only fix errors that applied before the rule change.

We could then merge those changes (the ones consistent with the original rules) but we will not change the set of rubocop rules in this project for the foreseeable future.

[Baelfire18]

Okay, totally understandable. Should I revert this commit to @rjherrera ?