v1.0.0-rc.4

Features:

• support for Schema URLs on the Resource and Tracer (Instrumentation Library)
• add force_flush to tracer provider and span processors
• add gzip compression option for exporter
• configuration improvements and Span limit settings
• add ssl options support to httpc exporter
• make trace/span id generation customizable
• add simple span processor
• add support for OTEL_SERVICE_NAME environment variable

Fixes/improvements:

• Remaining validations
• move zipkin exporter to main repo
• Support limits on attributes, links and events
• move the rest of application env vars to configuration map
• tracers: store startup created tracers the same way as user created
• exporter: update trace protos to v0.11.0
• fix docs local_parent_not_sampled
• fix: Removes macro that references missing function
• batch_processor: go to idle state after export timeout
• skip exporting if batch table is empty
• use get_application_tracer in Elixir macros
• exporter: support hosts and paths as binary or list strings
• remove sampler option to start_span and with_span
• make TracerProvider simply implement a gen_server
• allowing the stacktrace to be logged
• improve exporter module documentation and readme
• w3c interop tests now run in CI
• fix otel_propagator_trace_context:extract/1 missing undefined check