Bump version to 0.12.0 and update changelog

Author: sfirrin

CHANGELOG.md

@@ -1,5 +1,11 @@
 # CHANGELOG
 
+# Version 12 / 2020-02-03
+
+- Defaults the DD_ENHANCED_METRICS option to `true`
+- If DD_ENHANCED_METRICS is enabled, always writes enhanced metrics to stdout
+- Note: if you previously had DD_ENHANCED_METRICS=true and did not set DD_FLUSH_TO_LOG=true, the enhanced metrics will no longer be submitted to Datadog synchonously; the metrics will now be written to logs. If you already have a Datadog Forwarder Lambda configured, that will read the enhanced metrics logs and submit the metrics asynchronously. If you do not have a Datadog Forwarder set up, you'll need to create one to get enhanced metrics into your Datadog account. See [Datadog Forwarder Lambda setup instructions](https://github.com/DataDog/datadog-serverless-functions/tree/master/aws/logs_monitoring).
+
 # Version 11 / 2019-12-06
 
 - Add python 3.8 support

datadog_lambda/__init__.py

@@ -1,9 +1,10 @@
 # The minor version corresponds to the Lambda layer version.
 # E.g.,, version 0.5.0 gets packaged into layer version 5.
-__version__ = '0.11.0'
+__version__ = "0.12.0"
 
 
 import os
 import logging
+
 logger = logging.getLogger(__name__)
-logger.setLevel(logging.getLevelName(os.environ.get('DD_LOG_LEVEL', 'INFO').upper()))
+logger.setLevel(logging.getLevelName(os.environ.get("DD_LOG_LEVEL", "INFO").upper()))