• Add support for zero or more callbacks
  (#2602)
• Fix parsing of trace flags when extracting traceparent
  (#2577)
• Add default aggregation
  (#2543)
• Fix incorrect installation of some exporter “convenience” packages into
  “site-packages/src”
  (#2525)
• Capture exception information as part of log attributes
  (#2531)
• Change OTLPHandler to LoggingHandler
  (#2528)
• Fix delta histogram sum not being reset on collection
  (#2533)
• Add InMemoryMetricReader to metrics SDK
  (#2540)
• Drop the usage of name field from log model in OTLP
  (#2565)
• Update opentelemetry-proto to v0.15.0
  (#2566)
• Remove enable_default_view option from sdk MeterProvider
  (#2547)
• Update otlp-proto-grpc and otlp-proto-http exporters to have more lax requirements for backoff lib
  (#2575)
• Add min/max to histogram point
  (#2581)