Use `Addressable::URI#inferred_port` for determining port
Use `Addressable::URI#inferred_port` for determining port

`#port` is often `nil`:

    [10] pry(main)> URI.parse("http://localhost").port
    => 80
    [11] pry(main)> Addressable::URI.parse("http://localhost").port
    => nil
    [12] pry(main)> Addressable::URI.parse("http://localhost").inferred_port
    => 80

Some URIs will still return `nil`, so we protect against those with `#to_i`.

travis-ci/travis-api,travis-ci/travis-api,travis-ci/travis-api