[#84257640] Update ChangeLog to start feature "Start on empty cluster"

https://www.pivotaltracker.com/story/show/84257640
[#84257640] Added pull request url to ChangeLog

https://github.com/zvelo/zvelo-discoverator/pull/2
added debug denoting service map had serious error during creation before bubbling up the error to handleError.
Now using RawGet instead of Get to fetch keys in etcd.  This allows for introspection of response code.  Warn if response code is 404, indicating there are no serices running (or registrator isn't running Return an empty service map in this case and continue execution.  If there was no error, then unmarshall the response to a normal response and continue.
Merge branch 'develop' into feature/84257640_lukekingland_start_on_empty_cluster
fix a few minor issues

Signed-off-by: Joshua Rubin <jrubin@zvelo.com>