Made properties public (#538) (#553)

(cherry picked from commit b4450a3)

Update CHANGELOG.md for the 0.6.0-alpha-1 version

Downgrade gradle-download-task

Use the 4.1.2 version where #516 is not reproduced.

Convert all the model types without constructor parameters to objects (…

…#492)

Release 0.4.0

Release 0.3 version

Fixed CHANGELOG.md

Merge branch 'master' of https://github.com/JetBrains/KotlinDL