#249 Enable animations with Jupyter notebooks

[Ulf Lorenz]

Note: Priority depends largely on how useful the virtual machine is for users.
Split off from [#238]

Jupyter notebooks interact in some strange ways with Python's Matplotlib. In particular, the animation workflow that wavepacket uses to plot the wavepacket is not well supported, but needs extra commands.

The task is to extend the Vagrantfile such that the animation workflow just works for ordinary users.

Guides: You apparently need a special backend (?) which you also need to activate in the notebook. So maybe a solution of installing the backend and having a notebook template or something like this.