* "#1081 Removed public class modifiers"

* Changed Meetup method to private per comments on Pull Request #1082

* Made Meetup method public again as it did not pass the checks for Pull Request #1082.

* Changed MeetupTest.java to private per comments on Pull Request #1082

* Made MeetupTest public again as it failed testing.

* Made Meetup method package-private per comments on Pull Request #1082.

* Corrected access modifiers per suggestions on Pull Request #1082.

Removed package-private from Meetup method and removed private from
cycleToPrev and cycleToNext methods.

* Added private access levels back to cycleToPrev and cycleToNext.

Per feedback on pull request #1082 added the private access levels back
to these two methods.

Reference solution directory was renamed and move to the
always-excluded-from-delivery .meta folder.

With exercism/exercism.io@54e1df3, we can now gather exercises into a
subdirectory. By separating the language track files from the
configuration and management files, it is easier to read the project.

- move gradle config under "exercises" too as it would make a mess
  otherwise.

- enable compilation during CI build only for those that currently pass.
  (let's tackle the failing tests+example code one at a time).

A straight port of the Ruby tests. The example implementation
uses Joda Time which is generally considered a saner date/time
library than what is built in to Java.