The new SDK 4.0 release is still in beta, so I've created an sdk-4.0 branch in the Alfresco Developer Series Tutorials project on GitHub. All of the tutorials in that project have been reconfigured to adhere to the new Docker-based, SDK 4.0 project setup.
Other than the project structure, nothing had to change in the actual source code for the tutorials to continue to work with Alfresco 6.0.
Currently, the tutorials on the master branch are still SDK 3.0.1. Once SDK 4.0 is GA I will merge the sdk-4.0 branch into master. Those that still need tutorials that use the older SDK can use the SDK-3.0.1 tag to check out the appropriate version.
If you find any issues in the tutorials with the new SDK 4.0 setup, please create an issue on GitHub.
Side-note: I used the Alfresco SDK Upgrader script to automate the upgrade of those projects. It saved a ton of time.