Packaging for release 14.0.0

[matteodepalo]

Description

Release a new major version since we've removed Ruby 2.7 from CI.

Checklist:

• [x] My commit message follow the pattern described in here
• [x] I have performed a self-review of my own code.
• [ ] I have added tests that prove my fix is effective or that my feature works.
• [x] I have updated the project documentation.
• [x] I have added a changelog line.

[paulomarg]

I think we'll need to also change the value for

s.required_ruby_version = ">= 2.6"

in the gemspec file, right?

[sle-c]

I think we'll need to also change the value for

s.required_ruby_version = ">= 2.6"

in the gemspec file, right?

Totally missed this in the review 😓

[matteodepalo]

Totally missed this too, thank you!