Create unittest specifically for musicexplorer functionality

[johentsch]

The http://musicexplorer.epfl.ch/ app (written in Dash) lets users create custom groups of pieces, creates control elements for DiMCAT analyzers and features and, upon clicking on "Analyze..." runs a Pipeline and shows the plot.

For better semi-automatic integration of future analyzers and features, DiMCAT needs a unittest that emulates the things that the app does. It should include the relevant steps from the analyze() function in the following source code file:

musicexplorer.zip

As a basic check it could test if result.plot() returns a Plotly object.

[huguesdevimeux]

Thanks for the assignment. I will take a look shortly.

[yrammos]

Alternatively, or in addition, we could implement end-to-end testing of the web app to simulate user interactions (e.g. using Cypress.io). This might be a more reassuring approach, as far as the web app itself is concerned.