Pipeline Diagrams

[csala]

Add a get_diagram method to MLPipeline which outputs a visual representation of the pipeline flow as a Graphviz diagram.

The diagram should include:

• The Pipeline Steps, including the step and primitive names
• The Pipeline Inputs and Outputs
• A visual representation of the context
• The block inputs and outputs, including both the names that the MLBlock sees and the variable names when storing the values in the context

The method should have the following arguments:

• fit: boolean value indicating whether to include the fit arguments or not. Defaults to True.
• image_path: path to where the diagram image will be stored. If None, a graphviz.Digraph object is returned. Defaults to None.

See the following references:

• Get Pipeline Inputs #112: Get Pipeline Inputs issue, which will need to be resolved before or alongside this one.
• Featuretools.EntitySet.plot method, which behaves somewhet similarly to what we want to achieve here and can be used as a reference.
• The Context Usage Examples documentation diagrams which can be used as inspiration of what the diagrams should end up looking like.