1.3.0rc1

New Features

• internal: Add support for Datadog trace tag propagation
• django: added DD_DJANGO_INSTRUMENT_TEMPLATES=false to allow tracing of Django template rendering.
• internal: Add sampling mechanism trace tag
• Add environment variables to write ddtrace logs to a file with DD_TRACE_LOG_FILE, DD_TRACE_LOG_FILE_LEVEL, and DD_TRACE_FILE_SIZE_BYTES
• Adds pytest-bdd integration to show more details in CI Visibility product.

Bug Fixes

• starlette: Add back removed aggregate_resources feature.
• fastapi: Add back removed aggregate_resources feature.
• aiomysql: fix AttributeError: __aenter__ when using cursors as context managers.
• asgi, starlette, fastapi: Exclude background tasks duration from web request spans.
• asgi: set the http.url tag using the hostname in the request header before defaulting to the hostname of the asgi server.
• mypy: Avoid parsing redis asyncio files when type checking Python 2
• starlette: Add back removed ddtrace.contrib.starlette.get_resource and ddtrace.contrib.starlette.span_modifier.
• fastapi: Add back removed ddtrace.contrib.fastapi.span_modifier.
• internal: fix exception raised for invalid values of DD_TRACE_X_DATADOG_TAGS_MAX_LENGTH.
• flask_caching: fix redis tagging after the v2.0 release.
• redis: create default Pin on asyncio client. Not having a Pin was resulting in no traces being produced for the async redis client.

Other Notes

• perf: don't encode default parent_id value.
• profiling: add support for protobuf >=4.0.