Create a function to clear persisted artifacts and execution logs.

[andresionek91]

It would be nice to have a option inside Marvin to delete all persisted artifacts and log records.

Use cases are:

1. When you need to be sure that the engine isn't loading a object other than the most recent one.
2. When you want to delete persisted artifacts to free some disk space.
3. When your project has changed dramatically and you want to delete all the persisted objects that were created before.

A solution would delete all files from Marvin Engine temp folder. And all objects from the .artifacts folder.

A call to the function would look like: marvin engine-clearartifacts marvin engine-clearlogs