Datadog

* [Added] Add environment variable to disable statsd metric collection. See [589](https://github.com/DataDog/datadogpy/pull/589). Thanks [dgzlopes](https://github.com/dgzlopes).
* [Added] [dogstatsd] Add support for distribution context manager and decorator. See [581](https://github.com/DataDog/datadogpy/pull/581). Thanks [dnlserrano](https://github.com/dnlserrano).
* [Added] [dogstatsd] sock.setblocking(0) for UDP socket. See [590](https://github.com/DataDog/datadogpy/pull/590).
* [Added] [dogstatsd] Add type information to some dogstatsd methods. See [579](https://github.com/DataDog/datadogpy/pull/579). Thanks [vishalkuo](https://github.com/vishalkuo).

* [Added] Improve user-agent header to include telemetry information. See [583](https://github.com/DataDog/datadogpy/pull/583).
* [Fixed] Use Python 2 compatible configparser explicitly. See [585](https://github.com/DataDog/datadogpy/pull/585). Thanks [Panfilwk](https://github.com/Panfilwk).
* [Fixed] Fix error after creating `.dogrc` when not answering `y` or `n` at the prompt. See [582](https://github.com/DataDog/datadogpy/pull/582). Thanks [NassimBounouas](https://github.com/NassimBounouas).

* [Fixed] Add `typing` and `configparser` dependencies for python versions that need it. See [572](https://github.com/DataDog/datadogpy/pull/572). Thanks [jairideout](https://github.com/jairideout).

* [Added] Add version as an importable variable and remove dependency on `pkg_resources`. See [566](https://github.com/DataDog/datadogpy/pull/566). Thanks [sjhewitt](https://github.com/sjhewitt).
* [Added] Initial support for Python type hints and Mypy type checking. See [565](https://github.com/DataDog/datadogpy/pull/565). Thanks [jairideout](https://github.com/jairideout).
* [Fixed] [dogstatsd] Correct inverted constants. See [568](https://github.com/DataDog/datadogpy/pull/568).
* [Changed] [dogstatsd] Size-based packetization for dogstatsd batched metrics . See [562](https://github.com/DataDog/datadogpy/pull/562).

* [Added] Add excluded_regions to POST/PUT AWS lib. See [552](https://github.com/DataDog/datadogpy/pull/552).
* [Added] Add support for DD_ENV, DD_SERVICE, and DD_VERSION environment variables. See [548](https://github.com/DataDog/datadogpy/pull/548).
* [Fixed] Fix dogwrap help output case. See [557](https://github.com/DataDog/datadogpy/pull/557). Thanks [deiga](https://github.com/deiga).
* [Fixed] Fix decode attribute error with options for py3. See [555](https://github.com/DataDog/datadogpy/pull/555).

* [Added] Add `Set` metric type to threadstats. See [545](https://github.com/DataDog/datadogpy/pull/545).
* [Added] Add enum for monitor types. See [544](https://github.com/DataDog/datadogpy/pull/544).
* [Added] Support DD_API_KEY environment variable in dogwrap. See [543](https://github.com/DataDog/datadogpy/pull/543).
* [Added] Add back telemetry to Dogstatsd client. See [533](https://github.com/DataDog/datadogpy/pull/533).
* [Fixed] Remove illegal characters from tags. See [517](https://github.com/DataDog/datadogpy/pull/517). Thanks [jirikuncar](https://github.com/jirikuncar).
* [Fixed] Fix syntax error in dogwrap timeout handler and always collect output. See [538](https://github.com/DataDog/datadogpy/pull/538). Thanks [Matt343](https://github.com/Matt343).