Release v3.6.0

New Features

• Added support for adding custom attributes directly to
  spans.
  These attributes will be visible when looking at spans in the Distributed
  Tracing UI.

  Example:

  txn := newrelic.FromContext(r.Context())
  sgmt := txn.StartSegment("segment1")
  defer sgmt.End()
  sgmt.AddAttribute("mySpanString", "hello")
  sgmt.AddAttribute("mySpanInt", 123)

• Custom attributes added to the transaction with txn.AddAttribute are now
  also added to the root Span Event and will be visible when looking at the
  span in the Distributed Tracing UI. These custom attributes can be disabled
  from all destinations using Config.Attributes.Exclude or disabled from Span
  Events specifically using Config.SpanEvents.Attributes.Exclude.

• Agent attributes added to the transaction are now also added to the root Span
  Event and will be visible when looking at the span in the Distributed Tracing
  UI. These attributes include the request.uri and the request.method along
  with all other attributes listed in the attributes section of our
  godocs.
  These agent attributes can be disabled from all destinations using
  Config.Attributes.Exclude or disabled from Span Events specifically using
  Config.SpanEvents.Attributes.Exclude.

Bug Fixes

• Fixed an issue where it was impossible to exclude the attributes
  error.class and error.message from the root Span Event. This issue has
  now been fixed. These attributes can now be excluded from all Span Events
  using Config.Attributes.Exclude or Config.SpanEvents.Attributes.Exclude.

• Fixed an issue that caused Go's data race warnings to trigger in certain situations
  when using the newrelic.NewRoundTripper. There were no reports of actual data corruption,
  but now the warnings should be resolved. Thank you to @blixt for bringing this to our
  attention!