add test

spec/datadog/tracing/tracer_spec.rb

@@ -126,6 +126,18 @@
             expect(span.get_tag('my')).to eq('tag')
           end
 
+          context 'contains version and span.service is not equal to the default tracer service' do
+            let(:tracer_options) { { default_service: 'global-service', tags: { 'version' => '1.1.0' } } }
+            let(:service) { 'my-service' }
+            it 'does not set version on the span' do
+              expect(tracer.default_service).to eq('global-service')
+              expect(span.service).not_to eq('my-service')
+
+              expect(tracer.tags).to include('version' => '1.1.0')
+              expect(span.tags).not_to include('version')
+            end
+          end
+
           context 'and default tags are set on the tracer' do
             let(:tracer_options) { { tags: default_tags } }