Transition from joda-time to new Java 8 time API

[philci52]

Joda-Time suggests transition to JSR-310 see the "About" section on the website.

http://www.joda.org/joda-time/

Joda-Time is the de facto standard date and time library for Java prior to Java SE 8. Users are now asked to migrate to java.time (JSR-310).

[avromf]

I'm guessing several users of EWS for Java are still using it with Java 7 (or even earlier).

[robneild]

I also needed to remove joda. I just did the code and created a pull request