Migrate ddtrace(v1) to datadog(v2).

.travis.yml

@@ -1,8 +1,8 @@
 sudo: false
 language: ruby
 rvm:
-  - 2.7
-  - 3.0
-  - 3.1
+  - 3.2
+  - 3.3
+  - 3.4
 script:
   - bundle exec rspec

opencensus-datadog.gemspec

@@ -21,11 +21,13 @@ Gem::Specification.new do |spec|
   spec.executables   = spec.files.grep(%r{^exe/}) { |f| File.basename(f) }
   spec.require_paths = ["lib"]
 
+  spec.required_ruby_version = ">= 3.2.0"
+
   spec.add_dependency 'msgpack'
   spec.add_dependency 'opencensus'
-  spec.add_dependency 'ddtrace', '~> 1.0'
+  spec.add_dependency 'datadog', '>= 2.0', '< 3.0'
 
   spec.add_development_dependency "bundler", ">= 1.16", "< 3.0"
-  spec.add_development_dependency "rake", "~> 10.0"
+  spec.add_development_dependency "rake", "~> 13.0"
   spec.add_development_dependency "rspec", "~> 3.0"
 end

spec/opencensus/trace/exporters/datadog_spec.rb

@@ -6,4 +6,23 @@
       expect(OpenCensus::Trace::Exporters::Datadog.log.level).to eq ::Logger::WARN
     end
   end
+
+  describe 'Datadog gem constants compatibility' do
+    let(:converter) { OpenCensus::Trace::Exporters::Datadog::Converter.new('test-service') }
+
+    it 'has access to TAG_SAMPLING_PRIORITY constant' do
+      expect(::Datadog::Tracing::Metadata::Ext::Distributed::TAG_SAMPLING_PRIORITY).to be_a(String)
+      expect(OpenCensus::Trace::Exporters::Datadog::Converter::DATADOG_SAMPLING_PRIORITY_KEY).to eq(
+        ::Datadog::Tracing::Metadata::Ext::Distributed::TAG_SAMPLING_PRIORITY
+      )
+    end
+
+    it 'has access to Priority::AUTO_KEEP constant' do
+      expect(::Datadog::Tracing::Sampling::Ext::Priority::AUTO_KEEP).to be_a(Integer)
+    end
+
+    it 'has access to Errors::TAG_MSG constant' do
+      expect(::Datadog::Tracing::Metadata::Ext::Errors::TAG_MSG).to be_a(String)
+    end
+  end
 end