v0.17.0

Changed

• Implement Serialize & Deserialize for Sampler, SpanLimits #622, #626
• Allow &'static str and string in span methods #654
• Allow String data in instrumentation library. #670
• Remove std::fmt::Debug and 'static requirements from TracerProvider,
  Tracer, and Span #664
• Remove unused Tracer::invalid method #683
• Split TracerProvider::tracer and TracerProvider::versioned_tracer methods #682
• Reduce dependency on futures crate #684
• Switch to parent context references #687
• Spec-compliant trace and span ids #689
• Optimize span creation internals #693
• Add instrumentation library to ShouldSample parameters #695

Fixed

• Fix default resource detection for tracer provider #641
• Detect service.name from OTEL_SERVICE_NAME and OTEL_RESOURCE_ATTRIBUTES #662
• Fix TraceState::valid_key crashes #665