Catch up to a whole slew of recent metrics changes (up to 3.0.0-BETA3).
No more default metrics registry or jmx reporter.
AdminServlet now has a 0-args ctor and uses servlet init params.
No more MetricName.
Package name change.
Different naming semantics for annotations.
Remove some unneeded dependencies
Bump some plugin versions
Remove another unneeded dependency
Move tests out of 'test' package
update slf4j version (only used in tests anyway)
make javadoc generation quiet
First tests of AdminServletModule
Remove * import
Remove serviceName param since it's only exposed on AdminServlet's index page which isn't even used.
Now tests both default and custom paths.