- tracer: add ignoreTags option (acd7c58a)
- reporter: report empty parent service key as "unknown" (22a89a58)
- reporter: rename http_request_duration_seconds_bucket to http_request_handler_duration_sec (b07b5212)
- metrics renamed http_request_duration_seconds_bucket to http_request_handler_duration_seconds_bucket
(b07b5212)
- example: add child operation (7a260dfa)
- reporter: report parent_service with http_request_duration_seconds (a06e2bc0)
- tracer: public getters for Span and SpanContext (a5b54c15)
- reporter: add Prometheus reporter (74c2b189)
- tracer: add Reference, Span, SpanContext and Tracer models (e87df8e5)