Change zk configs to use Jackson injection instead of Skife

In an effort to make configuration more standard across various portions of the Druid modules, things are slowly migrating over to the Jackson configuration bindings instead of using the skife configuration stuff. This is but one portion of that overall migration.
the default should be set in the constructor, just like we do for all our
jackson annotated classes.
Jackson will pass null for undefined values.

On Thu, Dec 4, 2014 at 3:27 PM, Charles Allen <notifications@github.com>
wrote:

> In server/src/main/java/io/druid/server/initialization/ZkPathsConfig.java:
>
> >    public String getAnnouncementsPath()
> >    {
> > -    return defaultPath("announcements");
> > +    return announcementsPath;
> > +  }
> > +
> > +  public void setAnnouncementsPath(String announcementsPath)
>
> I haven't tried it yet, can Jackson overwrite a final value if it has a
> default value assigned to it?
>
> —
> Reply to this email directly or view it on GitHub
> <https://github.com/metamx/druid/pull/920/files#r21345111>.
>