Remove cucumber dependency to wire

[aurelien-reeves]

Description

Refs. https://github.com/cucumber/cucumber-ruby/pull/1562

cucumber-ruby-wire has been design to be an external optional dependency to cucumber-ruby. This is not the case yet and it is responsible for adding complexity in the dependency tree for cucumber-ruby.

This PR aims to make sure cucumber-ruby-wire works with a version of cucumber-ruby which does not depend on wire.

There will certainly be a deprecation phase before definitely removing dependency of cucumber-wire from cucumber.

Type of change

• Refactoring/debt (improvement to code design or tooling without changing behaviour)
• Breaking change (will cause existing functionality to not work as expected)

Note to other contributors

The addition of a "require_wire.rb" in the feature's backgrounds is due to the use of Aruba. In a regular use case that require 'cucumber/wire' would be done once by the user at the beginning of the test-suite. But with Aruba we are building a test-suite during the test-suite 😵

Still, we have to make sure it is working as expected in a regular use case, and document it as well.

Checklist:

• [X] My code follows the code style of this project.
• [X] My change requires a change to the documentation.
• [x] I have updated the documentation accordingly.
• [X] I have read the CONTRIBUTING document.
• [X] I have added/updated tests to cover my changes.
• [X] All new and existing tests passed.
• [x] CHANGELOG entry

[aurelien-reeves]

I've added an UPGRADING.md document, and change the version numbers of incoming cucumber from 8.0.0 and 9.0.0 to 7.1.0 and 8.0.0.