Backwards Incompatible Changes
* `Metric.from_value` is removed, replaced with metric constructor
* `CountMetric` / `SummaryMetric` `interval_ms` must be specified
* `Harvester.record` is removed and replaced with `Harvester.batch.record` (or simply `Batch.record`)
* `MetricBatch.record` method is removed, replaced with `MetricBatch.record_gauge`, `MetricBatch.record_count`, `MetricBatch.record_summary`
* `MetricBatch.create_identity` interface has been changed to accept name(str), tags (dict), and metric type (str)
New Features
Add HTTP proxy support for all clients (30)
The telemetry SDK now supports HTTP proxies specified via environment variable and for MacOS/Windows via the operating system registry.
Bug Fixes
Harvesters now close the client on stop.
When using the harvester, the client was not closed when the harvester was stopped via the `Harvester.stop` interface. Clients are now closed when the harvester is stopped.