Provide meaningful evidence of type "model"

[LiFaytheGoblin]

The "model" evidence currently is a .ser file, a serialization of a Linear Regression model. However, it can not be imported back into Moodle, nor can it's details (like weights) be viewed. A helpful file should be provided instead.

For the model evidence, generate a CSV that contains

• the model properties (fields as strings)
• for the Linear Regression model: the weights and model properties (e.g. learning rate)