v0.20.0

Bug Fixes

• java: correctly search for protected override implementations (#905) (e3f0f6c), closes #903
• java,dotnet: emit default implementations for optional properties (#906) (37ddfd5), closes #543
• kernel: correct deserialization of structs in union contexts (#919) (c0f338e), closes #822 aws/aws-cdk#3917 aws/aws-cdk#2013
• pacmak: fix a couple of issues related to java generation (#921) (5ad58c0)
• pacmak/python: improve detection of twine (#845) (2c4ef29)

Features

• update Dockerfile to .NET SDK 3.1, improve NuGet metadata (#880) (5e076cf)
• java: offer Builders for certain Java classes (#895) (f9c1335), closes #488
• kernel: annotate implemented interfaces on "ObjRef"s (#825) (a4e2095)
• pacmak: build all java targets at once (#849) (5d7824d)
• pacmak: put translated README into module docstring (#900) (8bacfb1)