Core Authoring
* [Nested conditional](https://github.com/flyteorg/flytekit/pull/479) (non-imperative only for now) now supported. Imperative style to come.
* Major cleanup of context object usage (internal).
Control Plane
* The `FlyteWorkflowExecution` and other execution related control plane objects have been [integrated](https://github.com/flyteorg/flytekit/pull/503/) with the flytekit type engine - inputs and outputs will now be converted into Python native values instead of showing the raw Flyte values.
Plugins
* Sqlite3 task type has been [updated](https://github.com/flyteorg/flytekit/pull/470) to make use of [pre-built](https://github.com/flyteorg/flytekit/blob/2f6efccd00ba7a8b7cc78855fcd96bd0b9c4b53b/flytekit/extras/sqlite3/task.py#L79 containers following the "shim task" style, this enables much more rapid iteration for the user as it obviates the time-consuming container build step.
Smaller Fixes
* Support for [shelling out](https://github.com/flyteorg/flytekit/pull/497) to authenticate, needed for better GCP integration.
* Both [IAM role and K8s](https://github.com/flyteorg/flytekit/pull/493) service account can be simultaneously used now.
* Labels and annotations specifiable on [Launch Plan creation](https://github.com/flyteorg/flytekit/pull/500)
* Serialization of elements no longer uses the older `SdkTask/Workflow/LaunchPlan` classes.
* Added a Dockerfile for flytekit itself, publishing a Debian buster image.