Add floating values for planet's degrees

[roabhi]

First of all thanks a lot for this amazing library and for making it public and free to use!

I noticed planets positions are rounded to a particular degree. I believe, as in most charts, planets are located within a degree in a particular position inside that degree (at least inside a given minute) which I would like to see implemented here.

Not sure if that is an optional feature or not. I do not see any reference to that in the documentation. If so, just close this issue.

If not, I could help implement that if you give me a few directions on where to start.

Thanks again.