Decouple dependency on Joda Time library to allow for other time-based implementations

[lu4nm3]

No description provided.

[joshlemer]

Not sure if you are aware of this, but in Java 8, most of joda time basically got pulled into the JDK, under the java.time package, and what didn't make it into the JDK was repackaged as https://www.threeten.org/threeten-extra/ if I understand correctly. Maybe we can just drop any dependency at all and use java.time, or possibly include threeten-extra.

[lu4nm3]

Ah, it's been a while since I used Java 8 heavily so I was not aware of this. I originally wanted to support some sort of type class pattern to support multiple time-based libraries besides Joda. However, from what you're saying, it looks like Java as a whole has converged on Joda's integration in Java 8 so it might make sense to just drop the dependency on Joda completely and rely on the defaults. I think this probably makes the most sense unless one day some new up-and-coming time library shows up which I find unlikely as Joda seems to have everything you could ever want. Thanks for pointing this out!