0.6.0

Update to the latest zeebe release (0.16.2):

• rename UpdatePayloadCommand to SetVariablesCommand
• rename all payload occurences to variables

This release is based on the zeebe 0.16.2 release (https://github.com/zeebe-io/zeebe).

Release is available via nuget (https://www.nuget.org/packages/zb-client).