Updates lombok dependency to remove need for tools.jar

[scottopell]

I reviewed the lombok changelog and I don't see anything that should cause issues (tested this locally as well).
The lombok issue that discusses this fix is a bit of a mess, but here it is.

Newer JDKs don't ship with tools.jar from what I understand, this should make it easier to work on this project with a wider variety of java dev environments

[scottopell]

Can't remove this dependency, lombok is not the only codepath that utilizes tools.jar

[ERROR] /home/circleci/project/src/main/java/org/datadog/jmxfetch/AttachApiConnection.java:[37,40] package com.sun.tools.attach does not exist

See https://github.com/DataDog/jmxfetch/blob/master/src/main/java/org/datadog/jmxfetch/AttachApiConnection.java#L38