Feature request: Add horizontal support

[dbartumeu]

Hi,

I'm using react nice dates in Ionic so far is pretty good.

I have a request, can you add animation / drag feature right to left as well. I see it only supports top bottom. What I'm asking is if it is possible to make it horizontal, that make much more sense to me cause the buttons to change month have an horizontal layout but the animation is vertical.

Thank you very much, Best regards.