Use SDKMAN! to download JDK

[ejba]

Describe the proposal

Changing the JDK every time you visit a project is always a stressful task. SDKMAN! makes life easier for developers by handling this part without a hassle.

The only requirement besides installing SDKMAN! of course, it is maintaining a configuration file with the JDK needed in the project. After that, developers just need to issue sdk env in the terminal to load the present configuration.