add ci-X.Y.Z to the tracer_version if datadog-ci is present and CI mo…

…de is enabled

lib/datadog/core/telemetry/request.rb

@@ -31,6 +31,12 @@ def build_payload(event, seq_id)
 
           def application
             config = Datadog.configuration
+
+            tracer_version = Core::Environment::Identity.gem_datadog_version_semver2
+            if config.respond_to?(:ci) && config.ci.enabled && defined?(::Datadog::CI::VERSION)
+              tracer_version = "#{tracer_version}+ci-#{::Datadog::CI::VERSION}"
+            end
+
             {
               env: config.env,
               language_name: Core::Environment::Ext::LANG,
@@ -39,7 +45,7 @@ def application
               runtime_version: Core::Environment::Ext::ENGINE_VERSION,
               service_name: config.service,
               service_version: config.version,
-              tracer_version: Core::Environment::Identity.gem_datadog_version_semver2
+              tracer_version: tracer_version
             }
           end