Remove Default Span Configuration

[aravinsiva]

Currently in Opentelemtry JS there is an instance of configuration for adding default span attributes. The use case for this overlaps heavily with the resource sdk. In addition seems this was just replicated from OpenCensus. Since this is just replicated functionality it is best to remove it.

The implementations can be found here:

• opentelemetry-js/packages/opentelemetry-node/src/NodeTracerProvider.ts

  Line 38 in e9b2cf9

  constructor(config: NodeTracerConfig = {}) {

• https://github.com/open-telemetry/opentelemetry-js/blob/master/packages/opentelemetry-tracing/src/types.ts#L30

[dyladan]

@mayurkale22 do you have any opinion here? I was not around in the OC days or when this was introduced.

My gut feeling is to remove it.

[mayurkale22]

I believe this field was there in the earlier version of specs. Seems like this concept is not present in other languages, I am fine to remove it.

[dyladan]

@aravinsiva are you planning on making a PR or should I mark this as up for grabs?

[aravinsiva]

I can go a head and take this on. No problem

[mayurkale22]

Closed via #1342