Change package name #1

Hi!

Thank you for providing this library! I was looking for something similar for a long time!

However, could you please move the classes from the default package to e.g. com.github.sritejakv.splitwise or something?
You cannot use Classes added through a Maven dependency located in the default package if the referencing class is not in the default package https://stackoverflow.com/a/15124546

Thank you very much!