WIP Starting to work on IPython support for pydy.viz

This PR is created to implement IPython notebook support for visualizations. 
1. My bad. they are same, typo error
2. Allow me to explain it in slight detail. 

So a user calls IPython_display. A visualization pops open in the output cell + some sliders to modify constants("l", "m", "g".. etc.), and a `rerun-calculations` button. Now a user plays with the slider, and when he hits the button(`rerun-calculations`), a call goes to `generate_visualization_json` with old values for rest of the arguments, but new values for constants("l", "m", "g".. etc.). So new data is generated and passed to visualization, which he can play. This is all what I have in mind as of now. If we wish to do `scipy.odeint` all over again, we need a `Simulator` class(what we discussed in last meeting), which can be implemented easily with the current implementation, by changing a few lines of code.