1.0.0-beta.0

Add tracing support

• sfx.wrapper now enables both metric and tracing by default.
• Users can set SIGNALFX_METRICS_ENABLED and SIGNALFX_TRACING_ENABLED env vars to "false" in order to disable either one.
• SIGNALFX_INGEST_ENDPOINT env var was removed in favor of SIGNALFX_ENDPOINT_URL and SIGNALFX_METRICS_URL.
• SIGNALFX_AUTH_TOKEN env var was renamed to SIGNALFX_ACCESS_TOKEN to be more consistent with other SignalFx libraries.
• access token can no longer be passed as an argument to the wrapper function and must be set using the SIGNALFX_ACCESS_TOKEN env var. This is the case because we initialize the tracer before wrapper functions are called and need the access token there.
• setAccessToken helper function was removed.
• setLambdaFunctionContext helper function was replaced with two new methods:
  • getExecutionMetadata(context) and
  • setDefaultDimension(dimensions, executionMetadata)