Add interface animations/transitions

[ruyadorno]

Although the styling is complete the app still lacks animations, those are essential for Material Design.

[stefanbuck]

@ruyadorno is this issue still valid? The current master looks pretty smooth to me!

[ruyadorno]

yeah, although material-ui really improved a lot the quality of animations in their components I still have some ideas in mind for the app interface, such as transitions when changing question prompts, smoother transition from clicking on a generator and opening the install process, etc