Added UPGRADING note.

Author: dblock

UPGRADING.md

@@ -1,5 +1,11 @@
 # Upgrading Strava-Ruby-Client
 
+### Upgrading to >= 2.3.0
+
+The signature of `Strava::Errors::RatelimitError` has changed with `message` calling `super`, and `headers`, and `errors` removed. Instead, use `message`, `response[:headers]` and `response[:body]['error']` respectively.
+
+See [#91](https://github.com/dblock/strava-ruby-client/pull/91) for details.
+
 ### Upgrading to >= 2.2.0
 
 Support for Ruby 2.x has been dropped. The minimum required Ruby version is now 3.0.0.
@@ -45,4 +51,4 @@ client = Strava::Api::Client.new(ca_file: OpenSSL::X509::DEFAULT_CERT_FILE, ca_p
 
 The library was upgraded to require Faraday 1.0 or newer. Change all references to `Faraday::Error::ResourceNotFound` or `Faraday::Error::ConnectionFailed` to `Faraday::ConnectionFailed` and `Faraday::ResourceNotFound` respectively.
 
-See [#30](https://github.com/dblock/strava-ruby-client/pull/30) for more details.
+See [#30](https://github.com/dblock/strava-ruby-client/pull/30) for details.

spec/strava/api/client_spec.rb

@@ -49,6 +49,9 @@
           expect(error.ratelimit.exceeded?).to be(true)
           expect(error.ratelimit.exceeded).to eql({ fifteen_minutes_remaining: 0 })
           expect(error.response[:request]).to be_nil
+          expect(error.message).to eq 'the server responded with status 429'
+          expect(error.response[:headers]).to be_a Hash
+          expect(error.response[:body]['error']).to eq 'Rate Limit Exceeded'
         end
       end
     end