Add chimera_http_client to http_clients.yml

[mediafinger]

Only adding a missing gem to the catalog.

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Thanks for contributing to the Ruby Toolbox catalog! ❤️

Before submitting your pull request:

• If you're referencing a gem by its GitHub repository (e.g. rails/rails), please verify
  that it is not packaged as a Ruby gem. (If it is packaged as a gem, please reference it
  by its gem name instead, e.g. rails.)
• Please make sure the projects are listed in case-insensitive alphabetical order
• Make sure the CI build passes, we validate your proposed changes in the test suite :)

[mediafinger]

The test suite fails with an error message that looks unrelated to my changes:

Failures:

  1) Catalog referenced rubygems references only actually existing gems
     Failure/Error: expect(referenced_gems - available_gems).to eq []

       expected: []
            got: ["mongoid-rating"]

And the gem mongoid-rating seems to exist: https://rubygems.org/gems/mongoid_rating so I don't know if I can do anything to fix the tests.

[colszowka]

Thank you @mediafinger 👋 , I rebased the branch and everything is fine now